131217857 has 4 divisors (see below), whose sum is σ = 138124080. Its totient is φ = 124311636.

The previous prime is 131217851. The next prime is 131217859. The reversal of 131217857 is 758712131.

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.

It is a cyclic number.

It is not a de Polignac number, because 131217857 - 2⁸ = 131217601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131217851) 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, 3453083 + ... + 3453120.

It is an arithmetic number, because the mean of its divisors is an integer number (34531020).

Almost surely, 2^131217857 is an apocalyptic number.

It is an amenable number.

131217857 is a deficient number, since it is larger than the sum of its proper divisors (6906223).

131217857 is an equidigital number, since it uses as much as digits as its factorization.

131217857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6906222.

The product of its digits is 11760, while the sum is 35.

The square root of 131217857 is about 11455.0363159616. The cubic root of 131217857 is about 508.1566892704.

Adding to 131217857 its reverse (758712131), we get a palindrome (889929988).

The spelling of 131217857 in words is "one hundred thirty-one million, two hundred seventeen thousand, eight hundred fifty-seven".