21024153656 has 48 divisors (see below), whose sum is σ = 43641742200. Its totient is φ = 9487621440.

The previous prime is 21024153643. The next prime is 21024153671. The reversal of 21024153656 is 65635142012.

It is a congruent number.

It is an unprimeable number.

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, 56426 + ... + 212678.

Almost surely, 2^21024153656 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 21024153656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21820871100).

21024153656 is an abundant number, since it is smaller than the sum of its proper divisors (22617588544).

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

21024153656 is a wasteful number, since it uses less digits than its factorization.

21024153656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156420 (or 156405 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 35.

Adding to 21024153656 its reverse (65635142012), we get a palindrome (86659295668).

The spelling of 21024153656 in words is "twenty-one billion, twenty-four million, one hundred fifty-three thousand, six hundred fifty-six".