131639491 has 4 divisors (see below), whose sum is σ = 131706400. Its totient is φ = 131572584.

The previous prime is 131639489. The next prime is 131639503. The reversal of 131639491 is 194936131.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 131639491 - 2¹ = 131639489 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 131639491.

It is not an unprimeable number, because it can be changed into a prime (131639401) 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, 30411 + ... + 34468.

It is an arithmetic number, because the mean of its divisors is an integer number (32926600).

Almost surely, 2^131639491 is an apocalyptic number.

131639491 is a deficient number, since it is larger than the sum of its proper divisors (66909).

131639491 is an equidigital number, since it uses as much as digits as its factorization.

131639491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66908.

The product of its digits is 17496, while the sum is 37.

The square root of 131639491 is about 11473.4254257393. The cubic root of 131639491 is about 508.7003832106.

The spelling of 131639491 in words is "one hundred thirty-one million, six hundred thirty-nine thousand, four hundred ninety-one".