21440124 has 36 divisors (see below), whose sum is σ = 54370680. Its totient is φ = 7123680.

The previous prime is 21440119. The next prime is 21440129. The reversal of 21440124 is 42104412.

It is an interprime number because it is at equal distance from previous prime (21440119) and next prime (21440129).

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a junction number, because it is equal to n+sod(n) for n = 21440097 and 21440106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21440129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13239 + ... + 14769.

Almost surely, 2^21440124 is an apocalyptic number.

It is an amenable number.

21440124 is an abundant number, since it is smaller than the sum of its proper divisors (32930556).

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

21440124 is a wasteful number, since it uses less digits than its factorization.

21440124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1930 (or 1925 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 21440124 is about 4630.3481510573. The cubic root of 21440124 is about 277.8065178915.

Adding to 21440124 its reverse (42104412), we get a palindrome (63544536).

The spelling of 21440124 in words is "twenty-one million, four hundred forty thousand, one hundred twenty-four".