20620651165 has 4 divisors (see below), whose sum is σ = 24744781404. Its totient is φ = 16496520928.

The previous prime is 20620651159. The next prime is 20620651187. The reversal of 20620651165 is 56115602602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5582779524 + 15037871641 = 74718^2 + 122629^2 .

It is a cyclic number.

It is not a de Polignac number, because 20620651165 - 2⁵ = 20620651133 is a prime.

It is a super-2 number, since 2×20620651165² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20620651165.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2062065112 + ... + 2062065121.

It is an arithmetic number, because the mean of its divisors is an integer number (6186195351).

Almost surely, 2^20620651165 is an apocalyptic number.

It is an amenable number.

20620651165 is a deficient number, since it is larger than the sum of its proper divisors (4124130239).

20620651165 is an equidigital number, since it uses as much as digits as its factorization.

20620651165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4124130238.

The product of its (nonzero) digits is 21600, while the sum is 34.

The spelling of 20620651165 in words is "twenty billion, six hundred twenty million, six hundred fifty-one thousand, one hundred sixty-five".