20992788621 has 24 divisors (see below), whose sum is σ = 34661727360. Its totient is φ = 11993468256.

The previous prime is 20992788613. The next prime is 20992788629. The reversal of 20992788621 is 12688729902.

20992788621 is a `hidden beast` number, since 2 + 0 + 9 + 9 + 2 + 7 + 8 + 8 + 621 = 666.

It is an interprime number because it is at equal distance from previous prime (20992788613) and next prime (20992788629).

It is not a de Polignac number, because 20992788621 - 2³ = 20992788613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20992788629) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 310240 + ... + 371798.

It is an arithmetic number, because the mean of its divisors is an integer number (1444238640).

Almost surely, 2^20992788621 is an apocalyptic number.

20992788621 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20992788621 is a deficient number, since it is larger than the sum of its proper divisors (13668938739).

20992788621 is a wasteful number, since it uses less digits than its factorization.

20992788621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66985 (or 66982 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 54.

The spelling of 20992788621 in words is "twenty billion, nine hundred ninety-two million, seven hundred eighty-eight thousand, six hundred twenty-one".