2131997279 has 4 divisors (see below), whose sum is σ = 2134235376. Its totient is φ = 2129759184.

The previous prime is 2131997261. The next prime is 2131997323. The reversal of 2131997279 is 9727991312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2131997279 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 (2131997209) 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, 1117619 + ... + 1119524.

It is an arithmetic number, because the mean of its divisors is an integer number (533558844).

Almost surely, 2^2131997279 is an apocalyptic number.

2131997279 is a deficient number, since it is larger than the sum of its proper divisors (2238097).

2131997279 is an equidigital number, since it uses as much as digits as its factorization.

2131997279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2238096.

The product of its digits is 428652, while the sum is 50.

The square root of 2131997279 is about 46173.5560575531. The cubic root of 2131997279 is about 1287.0503845456.

The spelling of 2131997279 in words is "two billion, one hundred thirty-one million, nine hundred ninety-seven thousand, two hundred seventy-nine".