2645605891 has 4 divisors (see below), whose sum is σ = 2646995112. Its totient is φ = 2644216672.

The previous prime is 2645605883. The next prime is 2645605913. The reversal of 2645605891 is 1985065462.

2645605891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 2645605891 - 2³ = 2645605883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2645605801) 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, 691750 + ... + 695563.

It is an arithmetic number, because the mean of its divisors is an integer number (661748778).

Almost surely, 2^2645605891 is an apocalyptic number.

2645605891 is a deficient number, since it is larger than the sum of its proper divisors (1389221).

2645605891 is a wasteful number, since it uses less digits than its factorization.

2645605891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1389220.

The product of its (nonzero) digits is 518400, while the sum is 46.

The square root of 2645605891 is about 51435.4536385167. The cubic root of 2645605891 is about 1383.0622139722.

The spelling of 2645605891 in words is "two billion, six hundred forty-five million, six hundred five thousand, eight hundred ninety-one".