21231657204 has 48 divisors (see below), whose sum is σ = 52606024128. Its totient is φ = 6641694208.

The previous prime is 21231657203. The next prime is 21231657211. The reversal of 21231657204 is 40275613212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231657203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 79179 + ... + 220754.

It is an arithmetic number, because the mean of its divisors is an integer number (1095958836).

Almost surely, 2^21231657204 is an apocalyptic number.

It is an amenable number.

21231657204 is an abundant number, since it is smaller than the sum of its proper divisors (31374366924).

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

21231657204 is a wasteful number, since it uses less digits than its factorization.

21231657204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300304 (or 300302 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 33.

The spelling of 21231657204 in words is "twenty-one billion, two hundred thirty-one million, six hundred fifty-seven thousand, two hundred four".