129525921 has 24 divisors (see below), whose sum is σ = 214643520. Its totient is φ = 73730016.

The previous prime is 129525917. The next prime is 129525923.

It is a happy number.

129525921 is a `hidden beast` number, since 12 + 9 + 52 + 592 + 1 = 666.

129525921 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 129525921 - 2² = 129525917 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129525923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13126 + ... + 20768.

It is an arithmetic number, because the mean of its divisors is an integer number (8943480).

Almost surely, 2^129525921 is an apocalyptic number.

It is an amenable number.

129525921 is a deficient number, since it is larger than the sum of its proper divisors (85117599).

129525921 is a wasteful number, since it uses less digits than its factorization.

129525921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7925 (or 7922 counting only the distinct ones).

The product of its digits is 16200, while the sum is 36.

The square root of 129525921 is about 11380.9455231101. The cubic root of 129525921 is about 505.9631600502.

The spelling of 129525921 in words is "one hundred twenty-nine million, five hundred twenty-five thousand, nine hundred twenty-one".