16399979 has 2 divisors, whose sum is σ = 16399980. Its totient is φ = 16399978.

The previous prime is 16399967. The next prime is 16399987. The reversal of 16399979 is 97999361.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16399979 is a prime.

It is a super-2 number, since 2×16399979² = 537918622400882, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 16399979.

It is not a weakly prime, because it can be changed into another prime (16399909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8199989 + 8199990.

It is an arithmetic number, because the mean of its divisors is an integer number (8199990).

Almost surely, 2^16399979 is an apocalyptic number.

16399979 is a deficient number, since it is larger than the sum of its proper divisors (1).

16399979 is an equidigital number, since it uses as much as digits as its factorization.

16399979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 826686, while the sum is 53.

The square root of 16399979 is about 4049.6887534723. The cubic root of 16399979 is about 254.0667101113.

It can be divided in two parts, 163999 and 79, that multiplied together give a palindrome (12955921).

The spelling of 16399979 in words is "sixteen million, three hundred ninety-nine thousand, nine hundred seventy-nine".