20564752511 has 4 divisors (see below), whose sum is σ = 20768364024. Its totient is φ = 20361141000.

The previous prime is 20564752501. The next prime is 20564752573. The reversal of 20564752511 is 11525746502.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20564752511 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 (20564752501) 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, 101805605 + ... + 101805806.

It is an arithmetic number, because the mean of its divisors is an integer number (5192091006).

Almost surely, 2^20564752511 is an apocalyptic number.

20564752511 is a deficient number, since it is larger than the sum of its proper divisors (203611513).

20564752511 is a wasteful number, since it uses less digits than its factorization.

20564752511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203611512.

The product of its (nonzero) digits is 84000, while the sum is 38.

The spelling of 20564752511 in words is "twenty billion, five hundred sixty-four million, seven hundred fifty-two thousand, five hundred eleven".