131533551 has 20 divisors (see below), whose sum is σ = 197509752. Its totient is φ = 87233328.

The previous prime is 131533543. The next prime is 131533579. The reversal of 131533551 is 155335131.

It is not a de Polignac number, because 131533551 - 2³ = 131533543 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131533511) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 11836 + ... + 20078.

Almost surely, 2^131533551 is an apocalyptic number.

131533551 is a deficient number, since it is larger than the sum of its proper divisors (65976201).

131533551 is an equidigital number, since it uses as much as digits as its factorization.

131533551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8452 (or 8443 counting only the distinct ones).

The product of its digits is 3375, while the sum is 27.

The square root of 131533551 is about 11468.8077409991. The cubic root of 131533551 is about 508.5638836908.

Adding to 131533551 its reverse (155335131), we get a palindrome (286868682).

The spelling of 131533551 in words is "one hundred thirty-one million, five hundred thirty-three thousand, five hundred fifty-one".