20645818768 has 20 divisors (see below), whose sum is σ = 40131580720. Its totient is φ = 10289281824.

The previous prime is 20645818723. The next prime is 20645818799. The reversal of 20645818768 is 86781854602.

It is a super-2 number, since 2×20645818768² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2096658 + ... + 2106481.

It is an arithmetic number, because the mean of its divisors is an integer number (2006579036).

Almost surely, 2^20645818768 is an apocalyptic number.

It is an amenable number.

20645818768 is a deficient number, since it is larger than the sum of its proper divisors (19485761952).

20645818768 is a wasteful number, since it uses less digits than its factorization.

20645818768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4203454 (or 4203448 counting only the distinct ones).

The product of its (nonzero) digits is 5160960, while the sum is 55.

The spelling of 20645818768 in words is "twenty billion, six hundred forty-five million, eight hundred eighteen thousand, seven hundred sixty-eight".