131521087 has 4 divisors (see below), whose sum is σ = 134319456. Its totient is φ = 128722720.

The previous prime is 131521069. The next prime is 131521111. The reversal of 131521087 is 780125131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 780125131 = 37 ⋅21084463.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131521087 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131521007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1399114 + ... + 1399207.

It is an arithmetic number, because the mean of its divisors is an integer number (33579864).

Almost surely, 2^131521087 is an apocalyptic number.

131521087 is a deficient number, since it is larger than the sum of its proper divisors (2798369).

131521087 is an equidigital number, since it uses as much as digits as its factorization.

131521087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2798368.

The product of its (nonzero) digits is 1680, while the sum is 28.

The square root of 131521087 is about 11468.2643412157. The cubic root of 131521087 is about 508.5478194992.

The spelling of 131521087 in words is "one hundred thirty-one million, five hundred twenty-one thousand, eighty-seven".