129521091 has 16 divisors (see below), whose sum is σ = 202180608. Its totient is φ = 72206400.

The previous prime is 129521083. The next prime is 129521099. The reversal of 129521091 is 190125921.

It is an interprime number because it is at equal distance from previous prime (129521083) and next prime (129521099).

It is not a de Polignac number, because 129521091 - 2³ = 129521083 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129521099) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74355 + ... + 76076.

It is an arithmetic number, because the mean of its divisors is an integer number (12636288).

Almost surely, 2^129521091 is an apocalyptic number.

129521091 is a deficient number, since it is larger than the sum of its proper divisors (72659517).

129521091 is a wasteful number, since it uses less digits than its factorization.

129521091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150482.

The product of its (nonzero) digits is 1620, while the sum is 30.

The square root of 129521091 is about 11380.7333243513. The cubic root of 129521091 is about 505.9568708781.

The spelling of 129521091 in words is "one hundred twenty-nine million, five hundred twenty-one thousand, ninety-one".