20721010899 has 32 divisors (see below), whose sum is σ = 29209415680. Its totient is φ = 13029831072.

The previous prime is 20721010897. The next prime is 20721010901. The reversal of 20721010899 is 99801012702.

It is an interprime number because it is at equal distance from previous prime (20721010897) and next prime (20721010901).

It is not a de Polignac number, because 20721010899 - 2¹ = 20721010897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20721010897) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22845204 + ... + 22846110.

It is an arithmetic number, because the mean of its divisors is an integer number (912794240).

Almost surely, 2^20721010899 is an apocalyptic number.

20721010899 is a deficient number, since it is larger than the sum of its proper divisors (8488404781).

20721010899 is a wasteful number, since it uses less digits than its factorization.

20721010899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2239.

The product of its (nonzero) digits is 18144, while the sum is 39.

The spelling of 20721010899 in words is "twenty billion, seven hundred twenty-one million, ten thousand, eight hundred ninety-nine".