20511088864621 has 4 divisors (see below), whose sum is σ = 21172736892544. Its totient is φ = 19849440836700.

The previous prime is 20511088864601. The next prime is 20511088864667. The reversal of 20511088864621 is 12646888011502.

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.

It is a cyclic number.

It is not a de Polignac number, because 20511088864621 - 2¹³ = 20511088856429 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 (20511088864601) 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, 330824013915 + ... + 330824013976.

It is an arithmetic number, because the mean of its divisors is an integer number (5293184223136).

Almost surely, 2^{20511088864621} is an apocalyptic number.

It is an amenable number.

20511088864621 is a deficient number, since it is larger than the sum of its proper divisors (661648027923).

20511088864621 is an equidigital number, since it uses as much as digits as its factorization.

20511088864621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661648027922.

The product of its (nonzero) digits is 1474560, while the sum is 52.

The spelling of 20511088864621 in words is "twenty trillion, five hundred eleven billion, eighty-eight million, eight hundred sixty-four thousand, six hundred twenty-one".