131555531 has 4 divisors (see below), whose sum is σ = 131676552. Its totient is φ = 131434512.

The previous prime is 131555509. The next prime is 131555549. The reversal of 131555531 is 135555131.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131555531 is a prime.

It is a super-2 number, since 2×131555531² = 34613715473383922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 131555494 and 131555503.

It is not an unprimeable number, because it can be changed into a prime (131555131) 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, 58865 + ... + 61058.

It is an arithmetic number, because the mean of its divisors is an integer number (32919138).

Almost surely, 2^131555531 is an apocalyptic number.

131555531 is a deficient number, since it is larger than the sum of its proper divisors (121021).

131555531 is a wasteful number, since it uses less digits than its factorization.

131555531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121020.

The product of its digits is 5625, while the sum is 29.

The square root of 131555531 is about 11469.7659522764. The cubic root of 131555531 is about 508.5922100797.

The spelling of 131555531 in words is "one hundred thirty-one million, five hundred fifty-five thousand, five hundred thirty-one".