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21431124 = 2232111323181
BaseRepresentation
bin101000111000…
…0001101010100
31111022210222100
41101300031110
520441243444
62043202100
7350106261
oct121601524
944283870
1021431124
1111108580
127216330
134594950
142bbc268
151d34e69
hex1470354

21431124 has 144 divisors (see below), whose sum is σ = 66777984. Its totient is φ = 5702400.

The previous prime is 21431119. The next prime is 21431129. The reversal of 21431124 is 42113412.

It is an interprime number because it is at equal distance from previous prime (21431119) and next prime (21431129).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21431097 and 21431106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431129) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 118314 + ... + 118494.

It is an arithmetic number, because the mean of its divisors is an integer number (463736).

Almost surely, 221431124 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21431124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33388992).

21431124 is an abundant number, since it is smaller than the sum of its proper divisors (45346860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21431124 is a wasteful number, since it uses less digits than its factorization.

21431124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238 (or 233 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 21431124 is about 4629.3761998783. The cubic root of 21431124 is about 277.7676404952.

Adding to 21431124 its reverse (42113412), we get a palindrome (63544536).

The spelling of 21431124 in words is "twenty-one million, four hundred thirty-one thousand, one hundred twenty-four".