21666527992 has 64 divisors (see below), whose sum is σ = 42812352000. Its totient is φ = 10269552384.

The previous prime is 21666527959. The next prime is 21666528007. The reversal of 21666527992 is 29972566612.

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, 1596628 + ... + 1610140.

It is an arithmetic number, because the mean of its divisors is an integer number (668943000).

Almost surely, 2^21666527992 is an apocalyptic number.

It is an amenable number.

21666527992 is a deficient number, since it is larger than the sum of its proper divisors (21145824008).

21666527992 is a wasteful number, since it uses less digits than its factorization.

21666527992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13700 (or 13696 counting only the distinct ones).

The product of its digits is 4898880, while the sum is 55.

The spelling of 21666527992 in words is "twenty-one billion, six hundred sixty-six million, five hundred twenty-seven thousand, nine hundred ninety-two".