20575956553 has 4 divisors (see below), whose sum is σ = 20823859728. Its totient is φ = 20328053380.

The previous prime is 20575956529. The next prime is 20575956571. The reversal of 20575956553 is 35565957502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 35565957502 = 2 ⋅17782978751.

It is a cyclic number.

It is not a de Polignac number, because 20575956553 - 2⁹ = 20575956041 is a prime.

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 20575956553.

It is not an unprimeable number, because it can be changed into a prime (20575956503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123951463 + ... + 123951628.

It is an arithmetic number, because the mean of its divisors is an integer number (5205964932).

Almost surely, 2^20575956553 is an apocalyptic number.

It is an amenable number.

20575956553 is a deficient number, since it is larger than the sum of its proper divisors (247903175).

20575956553 is an equidigital number, since it uses as much as digits as its factorization.

20575956553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247903174.

The product of its (nonzero) digits is 7087500, while the sum is 52.

The spelling of 20575956553 in words is "twenty billion, five hundred seventy-five million, nine hundred fifty-six thousand, five hundred fifty-three".