Search a number
-
+
21370020 = 22357174173
BaseRepresentation
bin101000110000…
…1010010100100
31111012201011020
41101201102210
520432320040
62042011140
7346433160
oct121412244
944181136
1021370020
1111076681
1271a6ab0
134572ba9
142ba3ca0
151d21cd0
hex14614a4

21370020 has 192 divisors, whose sum is σ = 75188736. Its totient is φ = 4423680.

The previous prime is 21370009. The next prime is 21370021. The reversal of 21370020 is 2007312.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (21370021) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 292704 + ... + 292776.

It is an arithmetic number, because the mean of its divisors is an integer number (391608).

Almost surely, 221370020 is an apocalyptic number.

21370020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21370020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37594368).

21370020 is an abundant number, since it is smaller than the sum of its proper divisors (53818716).

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

21370020 is a wasteful number, since it uses less digits than its factorization.

21370020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 15.

The square root of 21370020 is about 4622.7718957353. The cubic root of 21370020 is about 277.5034006563.

Adding to 21370020 its reverse (2007312), we get a palindrome (23377332).

The spelling of 21370020 in words is "twenty-one million, three hundred seventy thousand, twenty".