131899991 has 8 divisors (see below), whose sum is σ = 139785264. Its totient is φ = 124028800.

The previous prime is 131899981. The next prime is 131900003. The reversal of 131899991 is 199998131.

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

It is a cyclic number.

It is not a de Polignac number, because 131899991 - 2²² = 127705687 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 (131899951) 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, 20516 + ... + 26166.

It is an arithmetic number, because the mean of its divisors is an integer number (17473158).

Almost surely, 2^131899991 is an apocalyptic number.

131899991 is a deficient number, since it is larger than the sum of its proper divisors (7885273).

131899991 is a wasteful number, since it uses less digits than its factorization.

131899991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7041.

The product of its digits is 157464, while the sum is 50.

The square root of 131899991 is about 11484.7721353103. The cubic root of 131899991 is about 509.0357160528.

The spelling of 131899991 in words is "one hundred thirty-one million, eight hundred ninety-nine thousand, nine hundred ninety-one".