131555521 has 8 divisors (see below), whose sum is σ = 132387840. Its totient is φ = 130726512.

The previous prime is 131555509. The next prime is 131555549. The reversal of 131555521 is 125555131.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 131555521 - 2²¹ = 129458369 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 131555521.

It is not an unprimeable number, because it can be changed into a prime (131555321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 148546 + ... + 149428.

It is an arithmetic number, because the mean of its divisors is an integer number (16548480).

Almost surely, 2^131555521 is an apocalyptic number.

It is an amenable number.

131555521 is a deficient number, since it is larger than the sum of its proper divisors (832319).

131555521 is an equidigital number, since it uses as much as digits as its factorization.

131555521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1655.

The product of its digits is 3750, while the sum is 28.

The square root of 131555521 is about 11469.7655163478. The cubic root of 131555521 is about 508.5921971931.

The spelling of 131555521 in words is "one hundred thirty-one million, five hundred fifty-five thousand, five hundred twenty-one".