129529521 has 24 divisors (see below), whose sum is σ = 206914656. Its totient is φ = 77423040.

The previous prime is 129529507. The next prime is 129529523. The reversal of 129529521 is 125925921.

It is a happy number.

129529521 is a `hidden beast` number, since 129 + 5 + 2 + 9 + 521 = 666.

It is not a de Polignac number, because 129529521 - 2⁹ = 129529009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129529523) 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, 1735 + ... + 16188.

It is an arithmetic number, because the mean of its divisors is an integer number (8621444).

Almost surely, 2^129529521 is an apocalyptic number.

129529521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

129529521 is a deficient number, since it is larger than the sum of its proper divisors (77385135).

129529521 is a wasteful number, since it uses less digits than its factorization.

129529521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18013 (or 18010 counting only the distinct ones).

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

The square root of 129529521 is about 11381.1036811023. The cubic root of 129529521 is about 505.9678475302.

The spelling of 129529521 in words is "one hundred twenty-nine million, five hundred twenty-nine thousand, five hundred twenty-one".