21709032 has 32 divisors (see below), whose sum is σ = 55020480. Its totient is φ = 7136640.

The previous prime is 21709027. The next prime is 21709063. The reversal of 21709032 is 23090712.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 21708993 and 21709011.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4444 + ... + 7947.

It is an arithmetic number, because the mean of its divisors is an integer number (1719390).

Almost surely, 2^21709032 is an apocalyptic number.

It is an amenable number.

21709032 is an abundant number, since it is smaller than the sum of its proper divisors (33311448).

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

21709032 is a wasteful number, since it uses less digits than its factorization.

21709032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12473 (or 12469 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 24.

The square root of 21709032 is about 4659.2952256752. The cubic root of 21709032 is about 278.9631379467.

Adding to 21709032 its reverse (23090712), we get a palindrome (44799744).

The spelling of 21709032 in words is "twenty-one million, seven hundred nine thousand, thirty-two".