20499990621 has 8 divisors (see below), whose sum is σ = 29818168224. Its totient is φ = 12424236720.

The previous prime is 20499990593. The next prime is 20499990653. The reversal of 20499990621 is 12609999402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20499990621 - 2⁶ = 20499990557 is a prime.

It is a super-2 number, since 2×20499990621² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20499990221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 310605886 + ... + 310605951.

It is an arithmetic number, because the mean of its divisors is an integer number (3727271028).

Almost surely, 2^20499990621 is an apocalyptic number.

It is an amenable number.

20499990621 is a deficient number, since it is larger than the sum of its proper divisors (9318177603).

20499990621 is a wasteful number, since it uses less digits than its factorization.

20499990621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 621211851.

The product of its (nonzero) digits is 629856, while the sum is 51.

The spelling of 20499990621 in words is "twenty billion, four hundred ninety-nine million, nine hundred ninety thousand, six hundred twenty-one".