2640640403 has 4 divisors (see below), whose sum is σ = 2685397080. Its totient is φ = 2595883728.

The previous prime is 2640640397. The next prime is 2640640411. The reversal of 2640640403 is 3040460462.

It is a happy number.

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 2640640403 - 2²⁶ = 2573531539 is a prime.

It is a super-3 number, since 3×2640640403³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2640640003) 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, 22378250 + ... + 22378367.

It is an arithmetic number, because the mean of its divisors is an integer number (671349270).

Almost surely, 2^2640640403 is an apocalyptic number.

2640640403 is a deficient number, since it is larger than the sum of its proper divisors (44756677).

2640640403 is an equidigital number, since it uses as much as digits as its factorization.

2640640403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44756676.

The product of its (nonzero) digits is 13824, while the sum is 29.

The square root of 2640640403 is about 51387.1618500185. The cubic root of 2640640403 is about 1382.1963909007.

The spelling of 2640640403 in words is "two billion, six hundred forty million, six hundred forty thousand, four hundred three".