20564515451 has 4 divisors (see below), whose sum is σ = 20564993400. Its totient is φ = 20564037504.

The previous prime is 20564515429. The next prime is 20564515453. The reversal of 20564515451 is 15451546502.

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

It is a cyclic number.

It is not a de Polignac number, because 20564515451 - 2¹⁰ = 20564514427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20564515453) 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, 167261 + ... + 262878.

It is an arithmetic number, because the mean of its divisors is an integer number (5141248350).

Almost surely, 2^20564515451 is an apocalyptic number.

20564515451 is a deficient number, since it is larger than the sum of its proper divisors (477949).

20564515451 is an equidigital number, since it uses as much as digits as its factorization.

20564515451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477948.

The product of its (nonzero) digits is 120000, while the sum is 38.

The spelling of 20564515451 in words is "twenty billion, five hundred sixty-four million, five hundred fifteen thousand, four hundred fifty-one".