2640631 has 8 divisors (see below), whose sum is σ = 3049760. Its totient is φ = 2239488.

The previous prime is 2640581. The next prime is 2640643. The reversal of 2640631 is 1360462.

2640631 is digitally balanced in base 8, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 10-Lehmer number, since φ(2640631) divides (2640631-1)¹⁰.

It is a cyclic number.

It is not a de Polignac number, because 2640631 - 2⁷ = 2640503 is a prime.

It is a super-2 number, since 2×2640631² = 13945864156322, which contains 22 as substring.

2640631 is strictly pandigital in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2641631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1266 + ... + 2623.

It is an arithmetic number, because the mean of its divisors is an integer number (381220).

2^2640631 is an apocalyptic number.

2640631 is a deficient number, since it is larger than the sum of its proper divisors (409129).

2640631 is an equidigital number, since it uses as much as digits as its factorization.

2640631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3993.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 2640631 is about 1625.0018461528. The cubic root of 2640631 is about 138.2194750288.

The spelling of 2640631 in words is "two million, six hundred forty thousand, six hundred thirty-one".