131231897 has 4 divisors (see below), whose sum is σ = 135465216. Its totient is φ = 126998580.

The previous prime is 131231851. The next prime is 131231909. The reversal of 131231897 is 798132131.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 798132131 = 23 ⋅34701397.

It is a cyclic number.

It is not a de Polignac number, because 131231897 - 2⁶ = 131231833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131234897) 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, 2116613 + ... + 2116674.

It is an arithmetic number, because the mean of its divisors is an integer number (33866304).

Almost surely, 2^131231897 is an apocalyptic number.

It is an amenable number.

131231897 is a deficient number, since it is larger than the sum of its proper divisors (4233319).

131231897 is an equidigital number, since it uses as much as digits as its factorization.

131231897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4233318.

The product of its digits is 9072, while the sum is 35.

The square root of 131231897 is about 11455.6491304509. The cubic root of 131231897 is about 508.1748124782.

The spelling of 131231897 in words is "one hundred thirty-one million, two hundred thirty-one thousand, eight hundred ninety-seven".