21644153232 has 40 divisors (see below), whose sum is σ = 60215145984. Its totient is φ = 6659739264.

The previous prime is 21644153191. The next prime is 21644153233. The reversal of 21644153232 is 23235144612.

It is a junction number, because it is equal to n+sod(n) for n = 21644153193 and 21644153202.

It is not an unprimeable number, because it can be changed into a prime (21644153233) 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 7 ways as a sum of consecutive naturals, for example, 17342448 + ... + 17343695.

Almost surely, 2^21644153232 is an apocalyptic number.

It is an amenable number.

21644153232 is an abundant number, since it is smaller than the sum of its proper divisors (38570992752).

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

21644153232 is a wasteful number, since it uses less digits than its factorization.

21644153232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34686167 (or 34686161 counting only the distinct ones).

The product of its digits is 34560, while the sum is 33.

Adding to 21644153232 its reverse (23235144612), we get a palindrome (44879297844).

The spelling of 21644153232 in words is "twenty-one billion, six hundred forty-four million, one hundred fifty-three thousand, two hundred thirty-two".