16978331 has 2 divisors, whose sum is σ = 16978332. Its totient is φ = 16978330.

The previous prime is 16978319. The next prime is 16978349. The reversal of 16978331 is 13387961.

It is a weak prime.

It is an emirp because it is prime and its reverse (13387961) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16978331 is a prime.

It is a super-2 number, since 2×16978331² = 576527447091122, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16978831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8489165 + 8489166.

It is an arithmetic number, because the mean of its divisors is an integer number (8489166).

Almost surely, 2^16978331 is an apocalyptic number.

16978331 is a deficient number, since it is larger than the sum of its proper divisors (1).

16978331 is an equidigital number, since it uses as much as digits as its factorization.

16978331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216, while the sum is 38.

The square root of 16978331 is about 4120.4770354899. The cubic root of 16978331 is about 257.0188633976.

The spelling of 16978331 in words is "sixteen million, nine hundred seventy-eight thousand, three hundred thirty-one".