131405257 has 4 divisors (see below), whose sum is σ = 139134996. Its totient is φ = 123675520.

The previous prime is 131405251. The next prime is 131405297. The reversal of 131405257 is 752504131.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 752504131 = 2953 ⋅254827.

It can be written as a sum of positive squares in 2 ways, for example, as 84290761 + 47114496 = 9181^2 + 6864^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131405257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131405251) 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, 3864844 + ... + 3864877.

It is an arithmetic number, because the mean of its divisors is an integer number (34783749).

Almost surely, 2^131405257 is an apocalyptic number.

131405257 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

131405257 is a deficient number, since it is larger than the sum of its proper divisors (7729739).

131405257 is an equidigital number, since it uses as much as digits as its factorization.

131405257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7729738.

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 131405257 is about 11463.2132057290. The cubic root of 131405257 is about 508.3984837635.

Adding to 131405257 its reverse (752504131), we get a palindrome (883909388).

The spelling of 131405257 in words is "one hundred thirty-one million, four hundred five thousand, two hundred fifty-seven".