131309551 has 4 divisors (see below), whose sum is σ = 138220600. Its totient is φ = 124398504.

The previous prime is 131309537. The next prime is 131309557. The reversal of 131309551 is 155903131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 155903131 = 23 ⋅6778397.

It is a cyclic number.

It is not a de Polignac number, because 131309551 - 2⁹ = 131309039 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 (131309557) 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, 3455496 + ... + 3455533.

It is an arithmetic number, because the mean of its divisors is an integer number (34555150).

Almost surely, 2^131309551 is an apocalyptic number.

131309551 is a deficient number, since it is larger than the sum of its proper divisors (6911049).

131309551 is an equidigital number, since it uses as much as digits as its factorization.

131309551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6911048.

The product of its (nonzero) digits is 2025, while the sum is 28.

The square root of 131309551 is about 11459.0379613648. The cubic root of 131309551 is about 508.2750270011.

The spelling of 131309551 in words is "one hundred thirty-one million, three hundred nine thousand, five hundred fifty-one".