20091912921 has 16 divisors (see below), whose sum is σ = 29840041920. Its totient is φ = 13361198400.

The previous prime is 20091912887. The next prime is 20091912979. The reversal of 20091912921 is 12921919002.

It is not a de Polignac number, because 20091912921 - 2⁶ = 20091912857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20091916921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 917035 + ... + 938688.

It is an arithmetic number, because the mean of its divisors is an integer number (1865002620).

Almost surely, 2^20091912921 is an apocalyptic number.

It is an amenable number.

20091912921 is a deficient number, since it is larger than the sum of its proper divisors (9748128999).

20091912921 is a wasteful number, since it uses less digits than its factorization.

20091912921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1856133 (or 1856127 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 36.

The spelling of 20091912921 in words is "twenty billion, ninety-one million, nine hundred twelve thousand, nine hundred twenty-one".