21618523992 has 64 divisors (see below), whose sum is σ = 58780078560. Its totient is φ = 6585984000.

The previous prime is 21618523973. The next prime is 21618524041. The reversal of 21618523992 is 29932581612.

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 15 ways as a sum of consecutive naturals, for example, 311509 + ... + 374532.

Almost surely, 2^21618523992 is an apocalyptic number.

It is an amenable number.

21618523992 is an abundant number, since it is smaller than the sum of its proper divisors (37161554568).

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

21618523992 is a wasteful number, since it uses less digits than its factorization.

21618523992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686164 (or 686160 counting only the distinct ones).

The product of its digits is 466560, while the sum is 48.

The spelling of 21618523992 in words is "twenty-one billion, six hundred eighteen million, five hundred twenty-three thousand, nine hundred ninety-two".