20651663775 has 48 divisors (see below), whose sum is σ = 36591657984. Its totient is φ = 10250570880.

The previous prime is 20651663771. The next prime is 20651663839. The reversal of 20651663775 is 57736615602.

It is not a de Polignac number, because 20651663775 - 2² = 20651663771 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20651663771) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 97959 + ... + 225608.

It is an arithmetic number, because the mean of its divisors is an integer number (762326208).

Almost surely, 2^20651663775 is an apocalyptic number.

20651663775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20651663775 is a deficient number, since it is larger than the sum of its proper divisors (15939994209).

20651663775 is a wasteful number, since it uses less digits than its factorization.

20651663775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323640 (or 323635 counting only the distinct ones).

The product of its (nonzero) digits is 1587600, while the sum is 48.

The spelling of 20651663775 in words is "twenty billion, six hundred fifty-one million, six hundred sixty-three thousand, seven hundred seventy-five".