20535664686 has 16 divisors (see below), whose sum is σ = 41684335104. Its totient is φ = 6743053944.

The previous prime is 20535664661. The next prime is 20535664733. The reversal of 20535664686 is 68646653502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25541470 + ... + 25542273.

It is an arithmetic number, because the mean of its divisors is an integer number (2605270944).

Almost surely, 2^20535664686 is an apocalyptic number.

20535664686 is an abundant number, since it is smaller than the sum of its proper divisors (21148670418).

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

20535664686 is a wasteful number, since it uses less digits than its factorization.

20535664686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51083815.

The product of its (nonzero) digits is 6220800, while the sum is 51.

The spelling of 20535664686 in words is "twenty billion, five hundred thirty-five million, six hundred sixty-four thousand, six hundred eighty-six".