129185957 has 4 divisors (see below), whose sum is σ = 132336876. Its totient is φ = 126035040.

The previous prime is 129185951. The next prime is 129185977. The reversal of 129185957 is 759581921.

It is a happy number.

It is a Cunningham number, because it is equal to 11366²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6220036 + 122965921 = 2494^2 + 11089^2 .

It is a cyclic number.

It is not a de Polignac number, because 129185957 - 2⁶ = 129185893 is a prime.

It is a super-2 number, since 2×129185957² = 33378022972011698, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129185951) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1575398 + ... + 1575479.

It is an arithmetic number, because the mean of its divisors is an integer number (33084219).

Almost surely, 2^129185957 is an apocalyptic number.

It is an amenable number.

129185957 is a deficient number, since it is larger than the sum of its proper divisors (3150919).

129185957 is an equidigital number, since it uses as much as digits as its factorization.

129185957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3150918.

The product of its digits is 226800, while the sum is 47.

The square root of 129185957 is about 11366.0000439908. Note that the first 4 decimals coincide. The cubic root of 129185957 is about 505.5201085283.

The spelling of 129185957 in words is "one hundred twenty-nine million, one hundred eighty-five thousand, nine hundred fifty-seven".