20665568553 has 32 divisors (see below), whose sum is σ = 32277504000. Its totient is φ = 11755811088.

The previous prime is 20665568551. The next prime is 20665568621. The reversal of 20665568553 is 35586556602.

It is not a de Polignac number, because 20665568553 - 2¹ = 20665568551 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20665568496 and 20665568505.

It is not an unprimeable number, because it can be changed into a prime (20665568551) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 184438 + ... + 274496.

It is an arithmetic number, because the mean of its divisors is an integer number (1008672000).

Almost surely, 2^20665568553 is an apocalyptic number.

It is an amenable number.

20665568553 is a deficient number, since it is larger than the sum of its proper divisors (11611935447).

20665568553 is an equidigital number, since it uses as much as digits as its factorization.

20665568553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90306 (or 90292 counting only the distinct ones).

The product of its (nonzero) digits is 6480000, while the sum is 51.

The spelling of 20665568553 in words is "twenty billion, six hundred sixty-five million, five hundred sixty-eight thousand, five hundred fifty-three".