20756757666 has 16 divisors (see below), whose sum is σ = 41515553664. Its totient is φ = 6918579504.

The previous prime is 20756757653. The next prime is 20756757667. The reversal of 20756757666 is 66675765702.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20756757667) 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, 68880 + ... + 215076.

It is an arithmetic number, because the mean of its divisors is an integer number (2594722104).

Almost surely, 2^20756757666 is an apocalyptic number.

20756757666 is an abundant number, since it is smaller than the sum of its proper divisors (20758795998).

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

20756757666 is a wasteful number, since it uses less digits than its factorization.

20756757666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169865.

The product of its (nonzero) digits is 22226400, while the sum is 57.

The spelling of 20756757666 in words is "twenty billion, seven hundred fifty-six million, seven hundred fifty-seven thousand, six hundred sixty-six".