20116640565 has 36 divisors (see below), whose sum is σ = 40561720524. Its totient is φ = 9196177536.

The previous prime is 20116640561. The next prime is 20116640567. The reversal of 20116640565 is 56504661102.

20116640565 is a `hidden beast` number, since 2 + 0 + 1 + 1 + 6 + 640 + 5 + 6 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5106960369 + 15009680196 = 71463^2 + 122514^2 .

It is not a de Polignac number, because 20116640565 - 2² = 20116640561 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20116640561) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 4559392 + ... + 4563801.

It is an arithmetic number, because the mean of its divisors is an integer number (1126714459).

Almost surely, 2^20116640565 is an apocalyptic number.

It is an amenable number.

20116640565 is an abundant number, since it is smaller than the sum of its proper divisors (20445079959).

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

20116640565 is a wasteful number, since it uses less digits than its factorization.

20116640565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9123218 (or 9123208 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 20116640565 in words is "twenty billion, one hundred sixteen million, six hundred forty thousand, five hundred sixty-five".