131515491 has 4 divisors (see below), whose sum is σ = 175353992. Its totient is φ = 87676992.

The previous prime is 131515469. The next prime is 131515499. The reversal of 131515491 is 194515131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194515131 = 3 ⋅64838377.

It is not a de Polignac number, because 131515491 - 2⁵ = 131515459 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131515499) 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, 21919246 + ... + 21919251.

It is an arithmetic number, because the mean of its divisors is an integer number (43838498).

Almost surely, 2^131515491 is an apocalyptic number.

131515491 is a deficient number, since it is larger than the sum of its proper divisors (43838501).

131515491 is an equidigital number, since it uses as much as digits as its factorization.

131515491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43838500.

The product of its digits is 2700, while the sum is 30.

The square root of 131515491 is about 11468.0203609865. The cubic root of 131515491 is about 508.5406067801.

The spelling of 131515491 in words is "one hundred thirty-one million, five hundred fifteen thousand, four hundred ninety-one".