21004021732 has 48 divisors (see below), whose sum is σ = 39281155200. Its totient is φ = 9798001920.

The previous prime is 21004021663. The next prime is 21004021769. The reversal of 21004021732 is 23712040012.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6543744 + ... + 6546952.

It is an arithmetic number, because the mean of its divisors is an integer number (818357400).

Almost surely, 2^21004021732 is an apocalyptic number.

It is an amenable number.

21004021732 is a deficient number, since it is larger than the sum of its proper divisors (18277133468).

21004021732 is a wasteful number, since it uses less digits than its factorization.

21004021732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4516 (or 4514 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 22.

Adding to 21004021732 its reverse (23712040012), we get a palindrome (44716061744).

The spelling of 21004021732 in words is "twenty-one billion, four million, twenty-one thousand, seven hundred thirty-two".