131661609 has 8 divisors (see below), whose sum is σ = 175619040. Its totient is φ = 87739296.

The previous prime is 131661553. The next prime is 131661623. The reversal of 131661609 is 906166131.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 131661609 - 2⁸ = 131661353 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 131661609.

It is not an unprimeable number, because it can be changed into a prime (131661109) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1789 + ... + 16325.

It is an arithmetic number, because the mean of its divisors is an integer number (21952380).

Almost surely, 2^131661609 is an apocalyptic number.

It is an amenable number.

131661609 is a deficient number, since it is larger than the sum of its proper divisors (43957431).

131661609 is a wasteful number, since it uses less digits than its factorization.

131661609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17559.

The product of its (nonzero) digits is 5832, while the sum is 33.

The square root of 131661609 is about 11474.3892647931. The cubic root of 131661609 is about 508.7288721412.

The spelling of 131661609 in words is "one hundred thirty-one million, six hundred sixty-one thousand, six hundred nine".