20977937566 has 16 divisors (see below), whose sum is σ = 32853953664. Its totient is φ = 10027145304.

The previous prime is 20977937557. The next prime is 20977937569. The reversal of 20977937566 is 66573977902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20977937569) 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, 50160 + ... + 210883.

It is an arithmetic number, because the mean of its divisors is an integer number (2053372104).

Almost surely, 2^20977937566 is an apocalyptic number.

20977937566 is a deficient number, since it is larger than the sum of its proper divisors (11876016098).

20977937566 is a wasteful number, since it uses less digits than its factorization.

20977937566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262815.

The product of its (nonzero) digits is 30005640, while the sum is 61.

The spelling of 20977937566 in words is "twenty billion, nine hundred seventy-seven million, nine hundred thirty-seven thousand, five hundred sixty-six".