131721091 has 6 divisors (see below), whose sum is σ = 138706460. Its totient is φ = 124741008.

The previous prime is 131721089. The next prime is 131721097. The reversal of 131721091 is 190127131.

It is not a de Polignac number, because 131721091 - 2¹ = 131721089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (131721097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 48711 + ... + 51343.

Almost surely, 2^131721091 is an apocalyptic number.

131721091 is a deficient number, since it is larger than the sum of its proper divisors (6985369).

131721091 is an frugal number, since it uses more digits than its factorization.

131721091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5285 (or 2652 counting only the distinct ones).

The product of its (nonzero) digits is 378, while the sum is 25.

The square root of 131721091 is about 11476.9809183426. The cubic root of 131721091 is about 508.8054716784.

The spelling of 131721091 in words is "one hundred thirty-one million, seven hundred twenty-one thousand, ninety-one".