129391131 has 8 divisors (see below), whose sum is σ = 182669904. Its totient is φ = 81186560.

The previous prime is 129391081. The next prime is 129391147. The reversal of 129391131 is 131193921.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 129391131 - 2⁹ = 129390619 is a prime.

It is a super-2 number, since 2×129391131² = 33484129562918322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (129321131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1268490 + ... + 1268591.

It is an arithmetic number, because the mean of its divisors is an integer number (22833738).

Almost surely, 2^129391131 is an apocalyptic number.

129391131 is a deficient number, since it is larger than the sum of its proper divisors (53278773).

129391131 is a wasteful number, since it uses less digits than its factorization.

129391131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2537101.

The product of its digits is 1458, while the sum is 30.

The square root of 129391131 is about 11375.0222417365. The cubic root of 129391131 is about 505.7875904440.

The spelling of 129391131 in words is "one hundred twenty-nine million, three hundred ninety-one thousand, one hundred thirty-one".