82131491 has 4 divisors (see below), whose sum is σ = 88449312. Its totient is φ = 75813672.

The previous prime is 82131463. The next prime is 82131499. The reversal of 82131491 is 19413128.

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 82131491 - 2¹⁰ = 82130467 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82131499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3158891 + ... + 3158916.

It is an arithmetic number, because the mean of its divisors is an integer number (22112328).

Almost surely, 2^82131491 is an apocalyptic number.

82131491 is a deficient number, since it is larger than the sum of its proper divisors (6317821).

82131491 is a wasteful number, since it uses less digits than its factorization.

82131491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6317820.

The product of its digits is 1728, while the sum is 29.

The square root of 82131491 is about 9062.6426057745. The cubic root of 82131491 is about 434.6802441618.

The spelling of 82131491 in words is "eighty-two million, one hundred thirty-one thousand, four hundred ninety-one".