20913622665 has 64 divisors (see below), whose sum is σ = 37797774336. Its totient is φ = 9804367872.

The previous prime is 20913622661. The next prime is 20913622693. The reversal of 20913622665 is 56622631902.

It is a happy number.

It is not a de Polignac number, because 20913622665 - 2² = 20913622661 is a prime.

It is a super-2 number, since 2×20913622665² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20913622661) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 308269 + ... + 369941.

It is an arithmetic number, because the mean of its divisors is an integer number (590590224).

Almost surely, 2^20913622665 is an apocalyptic number.

It is an amenable number.

20913622665 is a deficient number, since it is larger than the sum of its proper divisors (16884151671).

20913622665 is a wasteful number, since it uses less digits than its factorization.

20913622665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61778.

The product of its (nonzero) digits is 233280, while the sum is 42.

The spelling of 20913622665 in words is "twenty billion, nine hundred thirteen million, six hundred twenty-two thousand, six hundred sixty-five".