129216931 has 2 divisors, whose sum is σ = 129216932. Its totient is φ = 129216930.

The previous prime is 129216911. The next prime is 129216943. The reversal of 129216931 is 139612921.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 129216931 - 2¹⁵ = 129184163 is a prime.

It is a super-2 number, since 2×129216931² = 33394030514117522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (129216911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64608465 + 64608466.

It is an arithmetic number, because the mean of its divisors is an integer number (64608466).

Almost surely, 2^129216931 is an apocalyptic number.

129216931 is a deficient number, since it is larger than the sum of its proper divisors (1).

129216931 is an equidigital number, since it uses as much as digits as its factorization.

129216931 is an evil number, because the sum of its binary digits is even.

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

The square root of 129216931 is about 11367.3625349067. The cubic root of 129216931 is about 505.5605069559.

The spelling of 129216931 in words is "one hundred twenty-nine million, two hundred sixteen thousand, nine hundred thirty-one".