2315991 has 4 divisors (see below), whose sum is σ = 3087992. Its totient is φ = 1543992.

The previous prime is 2315983. The next prime is 2315993. The reversal of 2315991 is 1995132.

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

It is not a de Polignac number, because 2315991 - 2³ = 2315983 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2315993) 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, 385996 + ... + 386001.

It is an arithmetic number, because the mean of its divisors is an integer number (771998).

2^2315991 is an apocalyptic number.

2315991 is a deficient number, since it is larger than the sum of its proper divisors (772001).

2315991 is an equidigital number, since it uses as much as digits as its factorization.

2315991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772000.

The product of its digits is 2430, while the sum is 30.

The square root of 2315991 is about 1521.8380334319. The cubic root of 2315991 is about 132.3058221349.

The spelling of 2315991 in words is "two million, three hundred fifteen thousand, nine hundred ninety-one".