2640326945 has 4 divisors (see below), whose sum is σ = 3168392340. Its totient is φ = 2112261552.

The previous prime is 2640326939. The next prime is 2640326957. The reversal of 2640326945 is 5496230462.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5496230462 = 2 ⋅2748115231.

It can be written as a sum of positive squares in 2 ways, for example, as 995781136 + 1644545809 = 31556^2 + 40553^2 .

It is a cyclic number.

It is not a de Polignac number, because 2640326945 - 2¹⁰ = 2640325921 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264032690 + ... + 264032699.

It is an arithmetic number, because the mean of its divisors is an integer number (792098085).

Almost surely, 2^2640326945 is an apocalyptic number.

It is an amenable number.

2640326945 is a deficient number, since it is larger than the sum of its proper divisors (528065395).

2640326945 is an equidigital number, since it uses as much as digits as its factorization.

2640326945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528065394.

The product of its (nonzero) digits is 311040, while the sum is 41.

The square root of 2640326945 is about 51384.1117953789. Note that the first 3 decimals coincide. The cubic root of 2640326945 is about 1382.1416973927.

The spelling of 2640326945 in words is "two billion, six hundred forty million, three hundred twenty-six thousand, nine hundred forty-five".