21157932 has 24 divisors (see below), whose sum is σ = 50703856. Its totient is φ = 6861888.

The previous prime is 21157921. The next prime is 21157933. The reversal of 21157932 is 23975112.

It is a self number, because there is not a number n which added to its sum of digits gives 21157932.

It is not an unprimeable number, because it can be changed into a prime (21157933) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23383 + ... + 24270.

Almost surely, 2^21157932 is an apocalyptic number.

It is an amenable number.

21157932 is an abundant number, since it is smaller than the sum of its proper divisors (29545924).

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

21157932 is a wasteful number, since it uses less digits than its factorization.

21157932 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47697 (or 47695 counting only the distinct ones).

The product of its digits is 3780, while the sum is 30.

The square root of 21157932 is about 4599.7752118989. The cubic root of 21157932 is about 276.5823139240.

The spelling of 21157932 in words is "twenty-one million, one hundred fifty-seven thousand, nine hundred thirty-two".