13129857 has 40 divisors (see below), whose sum is σ = 21757736. Its totient is φ = 7838208.

The previous prime is 13129841. The next prime is 13129861. The reversal of 13129857 is 75892131.

It can be written as a sum of positive squares in 4 ways, for example, as 1185921 + 11943936 = 1089^2 + 3456^2 .

It is not a de Polignac number, because 13129857 - 2⁴ = 13129841 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13129807) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 38793 + ... + 39129.

Almost surely, 2^13129857 is an apocalyptic number.

It is an amenable number.

13129857 is a deficient number, since it is larger than the sum of its proper divisors (8627879).

13129857 is a wasteful number, since it uses less digits than its factorization.

13129857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399 (or 390 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 13129857 is about 3623.5144542281. The cubic root of 13129857 is about 235.9137923666.

The spelling of 13129857 in words is "thirteen million, one hundred twenty-nine thousand, eight hundred fifty-seven".