2640931 has 4 divisors (see below), whose sum is σ = 2702392. Its totient is φ = 2579472.

The previous prime is 2640919. The next prime is 2640941. The reversal of 2640931 is 1390462.

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-2640931 is a prime.

It is a super-2 number, since 2×2640931² = 13949033093522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2640896 and 2640905.

It is not an unprimeable number, because it can be changed into a prime (2640901) 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, 30666 + ... + 30751.

It is an arithmetic number, because the mean of its divisors is an integer number (675598).

2^2640931 is an apocalyptic number.

2640931 is a deficient number, since it is larger than the sum of its proper divisors (61461).

2640931 is an equidigital number, since it uses as much as digits as its factorization.

2640931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61460.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 2640931 is about 1625.0941511186. The cubic root of 2640931 is about 138.2247091656.

The spelling of 2640931 in words is "two million, six hundred forty thousand, nine hundred thirty-one".