21487932 has 36 divisors (see below), whose sum is σ = 57513456. Its totient is φ = 6741120.

The previous prime is 21487919. The next prime is 21487951. The reversal of 21487932 is 23978412.

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 (36).

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, 16944 + ... + 18167.

It is an arithmetic number, because the mean of its divisors is an integer number (1597596).

Almost surely, 2^21487932 is an apocalyptic number.

It is an amenable number.

21487932 is an abundant number, since it is smaller than the sum of its proper divisors (36025524).

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

21487932 is a wasteful number, since it uses less digits than its factorization.

21487932 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35138 (or 35133 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 21487932 is about 4635.5077391803. The cubic root of 21487932 is about 278.0128524327.

The spelling of 21487932 in words is "twenty-one million, four hundred eighty-seven thousand, nine hundred thirty-two".