131809257 has 12 divisors (see below), whose sum is σ = 190494720. Its totient is φ = 87825048.

The previous prime is 131809253. The next prime is 131809283. The reversal of 131809257 is 752908131.

It is not a de Polignac number, because 131809257 - 2² = 131809253 is a prime.

It is not an unprimeable number, because it can be changed into a prime (131809253) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23368 + ... + 28454.

It is an arithmetic number, because the mean of its divisors is an integer number (15874560).

Almost surely, 2^131809257 is an apocalyptic number.

It is an amenable number.

131809257 is a deficient number, since it is larger than the sum of its proper divisors (58685463).

131809257 is a wasteful number, since it uses less digits than its factorization.

131809257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7972 (or 7969 counting only the distinct ones).

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

The square root of 131809257 is about 11480.8212685330. The cubic root of 131809257 is about 508.9189673935.

The spelling of 131809257 in words is "one hundred thirty-one million, eight hundred nine thousand, two hundred fifty-seven".