21013232 has 20 divisors (see below), whose sum is σ = 40789800. Its totient is φ = 10486848.

The previous prime is 21013217. The next prime is 21013249. The reversal of 21013232 is 23231012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11519 + ... + 13217.

It is an arithmetic number, because the mean of its divisors is an integer number (2039490).

Almost surely, 2^21013232 is an apocalyptic number.

It is an amenable number.

21013232 is a deficient number, since it is larger than the sum of its proper divisors (19776568).

21013232 is a wasteful number, since it uses less digits than its factorization.

21013232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2480 (or 2474 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21013232 is about 4584.0191971675. The cubic root of 21013232 is about 275.9503516380.

Adding to 21013232 its reverse (23231012), we get a palindrome (44244244).

The spelling of 21013232 in words is "twenty-one million, thirteen thousand, two hundred thirty-two".