21902657816 has 32 divisors (see below), whose sum is σ = 46554236400. Its totient is φ = 9576869760.

The previous prime is 21902657813. The next prime is 21902657849. The reversal of 21902657816 is 61875620912.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21902657813) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5540195 + ... + 5544146.

Almost surely, 2^21902657816 is an apocalyptic number.

21902657816 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21902657816 is an abundant number, since it is smaller than the sum of its proper divisors (24651578584).

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

21902657816 is a wasteful number, since it uses less digits than its factorization.

21902657816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11084379 (or 11084375 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 47.

The spelling of 21902657816 in words is "twenty-one billion, nine hundred two million, six hundred fifty-seven thousand, eight hundred sixteen".