20765181064 has 8 divisors (see below), whose sum is σ = 38934714510. Its totient is φ = 10382590528.

The previous prime is 20765181053. The next prime is 20765181067. The reversal of 20765181064 is 46018156702.

It can be written as a sum of positive squares in only one way, i.e., 20695124164 + 70056900 = 143858^2 + 8370^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (20765181067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1297823809 + ... + 1297823824.

Almost surely, 2^20765181064 is an apocalyptic number.

It is an amenable number.

20765181064 is a deficient number, since it is larger than the sum of its proper divisors (18169533446).

20765181064 is a wasteful number, since it uses less digits than its factorization.

20765181064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2595647639 (or 2595647635 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 40.

The spelling of 20765181064 in words is "twenty billion, seven hundred sixty-five million, one hundred eighty-one thousand, sixty-four".