16556342399 has 2 divisors, whose sum is σ = 16556342400. Its totient is φ = 16556342398.

The previous prime is 16556342377. The next prime is 16556342401. The reversal of 16556342399 is 99324365561.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16556342399 is a prime.

It is a super-2 number, since 2×16556342399² (a number of 21 digits) contains 22 as substring.

Together with 16556342401, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16556342399.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16556342339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8278171199 + 8278171200.

It is an arithmetic number, because the mean of its divisors is an integer number (8278171200).

Almost surely, 2^16556342399 is an apocalyptic number.

16556342399 is a deficient number, since it is larger than the sum of its proper divisors (1).

16556342399 is an equidigital number, since it uses as much as digits as its factorization.

16556342399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5248800, while the sum is 53.

The spelling of 16556342399 in words is "sixteen billion, five hundred fifty-six million, three hundred forty-two thousand, three hundred ninety-nine".