129931291 has 24 divisors (see below), whose sum is σ = 161551680. Its totient is φ = 103883472.

The previous prime is 129931283. The next prime is 129931297. The reversal of 129931291 is 192139921.

It is a happy number.

It is not a de Polignac number, because 129931291 - 2³ = 129931283 is a prime.

It is a super-5 number, since 5×129931291⁵ (a number of 42 digits) contains 55555 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 129931291.

It is not an unprimeable number, because it can be changed into a prime (129931297) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 61336 + ... + 63418.

It is an arithmetic number, because the mean of its divisors is an integer number (6731320).

Almost surely, 2^129931291 is an apocalyptic number.

129931291 is a deficient number, since it is larger than the sum of its proper divisors (31620389).

129931291 is a wasteful number, since it uses less digits than its factorization.

129931291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2183 (or 2176 counting only the distinct ones).

The product of its digits is 8748, while the sum is 37.

The square root of 129931291 is about 11398.7407637861. The cubic root of 129931291 is about 506.4904385289.

The spelling of 129931291 in words is "one hundred twenty-nine million, nine hundred thirty-one thousand, two hundred ninety-one".