21012916039 has 4 divisors (see below), whose sum is σ = 21015577440. Its totient is φ = 21010254640.

The previous prime is 21012916007. The next prime is 21012916061. The reversal of 21012916039 is 93061921012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21012916039 - 2⁵ = 21012916007 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21012915995 and 21012916013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012986039) 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, 1318822 + ... + 1334659.

It is an arithmetic number, because the mean of its divisors is an integer number (5253894360).

Almost surely, 2^21012916039 is an apocalyptic number.

21012916039 is a deficient number, since it is larger than the sum of its proper divisors (2661401).

21012916039 is an equidigital number, since it uses as much as digits as its factorization.

21012916039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2661400.

The product of its (nonzero) digits is 5832, while the sum is 34.

The spelling of 21012916039 in words is "twenty-one billion, twelve million, nine hundred sixteen thousand, thirty-nine".