129135381 has 16 divisors (see below), whose sum is σ = 181708800. Its totient is φ = 81349488.

The previous prime is 129135379. The next prime is 129135389. The reversal of 129135381 is 183531921.

It is not a de Polignac number, because 129135381 - 2¹ = 129135379 is a prime.

It is a super-2 number, since 2×129135381² = 33351893252030322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129135389) 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, 21180 + ... + 26586.

It is an arithmetic number, because the mean of its divisors is an integer number (11356800).

Almost surely, 2^129135381 is an apocalyptic number.

It is an amenable number.

129135381 is a deficient number, since it is larger than the sum of its proper divisors (52573419).

129135381 is a wasteful number, since it uses less digits than its factorization.

129135381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5848.

The product of its digits is 6480, while the sum is 33.

The square root of 129135381 is about 11363.7749449732. The cubic root of 129135381 is about 505.4541299374.

The spelling of 129135381 in words is "one hundred twenty-nine million, one hundred thirty-five thousand, three hundred eighty-one".