16391516639 has 2 divisors, whose sum is σ = 16391516640. Its totient is φ = 16391516638.

The previous prime is 16391516633. The next prime is 16391516641. The reversal of 16391516639 is 93661519361.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16391516639 - 2²⁰ = 16390468063 is a prime.

It is a super-2 number, since 2×16391516639² (a number of 21 digits) contains 22 as substring.

Together with 16391516641, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16391516633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8195758319 + 8195758320.

It is an arithmetic number, because the mean of its divisors is an integer number (8195758320).

Almost surely, 2^16391516639 is an apocalyptic number.

16391516639 is a deficient number, since it is larger than the sum of its proper divisors (1).

16391516639 is an equidigital number, since it uses as much as digits as its factorization.

16391516639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 787320, while the sum is 50.

The spelling of 16391516639 in words is "sixteen billion, three hundred ninety-one million, five hundred sixteen thousand, six hundred thirty-nine".