131919661 has 4 divisors (see below), whose sum is σ = 132311452. Its totient is φ = 131527872.

The previous prime is 131919659. The next prime is 131919691. The reversal of 131919661 is 166919131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166919131 = 5903 ⋅28277.

It can be written as a sum of positive squares in 2 ways, for example, as 40717161 + 91202500 = 6381^2 + 9550^2 .

It is a cyclic number.

It is not a de Polignac number, because 131919661 - 2¹ = 131919659 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 131919661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131919691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 195390 + ... + 196063.

It is an arithmetic number, because the mean of its divisors is an integer number (33077863).

Almost surely, 2^131919661 is an apocalyptic number.

It is an amenable number.

131919661 is a deficient number, since it is larger than the sum of its proper divisors (391791).

131919661 is an equidigital number, since it uses as much as digits as its factorization.

131919661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391790.

The product of its digits is 8748, while the sum is 37.

The square root of 131919661 is about 11485.6284547255. The cubic root of 131919661 is about 509.0610186445.

The spelling of 131919661 in words is "one hundred thirty-one million, nine hundred nineteen thousand, six hundred sixty-one".