20556225551 has 16 divisors (see below), whose sum is σ = 21969978624. Its totient is φ = 19186689984.

The previous prime is 20556225541. The next prime is 20556225553. The reversal of 20556225551 is 15552265502.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20556225551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20556225553) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1075460 + ... + 1094406.

It is an arithmetic number, because the mean of its divisors is an integer number (1373123664).

Almost surely, 2^20556225551 is an apocalyptic number.

20556225551 is a deficient number, since it is larger than the sum of its proper divisors (1413753073).

20556225551 is a wasteful number, since it uses less digits than its factorization.

20556225551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20110.

The product of its (nonzero) digits is 150000, while the sum is 38.

The spelling of 20556225551 in words is "twenty billion, five hundred fifty-six million, two hundred twenty-five thousand, five hundred fifty-one".