2640370709 has 4 divisors (see below), whose sum is σ = 2653773804. Its totient is φ = 2626967616.

The previous prime is 2640370699. The next prime is 2640370717. The reversal of 2640370709 is 9070730462.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1572519025 + 1067851684 = 39655^2 + 32678^2 .

It is a cyclic number.

It is not a de Polignac number, because 2640370709 - 2⁴ = 2640370693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2640375709) 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, 6701252 + ... + 6701645.

It is an arithmetic number, because the mean of its divisors is an integer number (663443451).

Almost surely, 2^2640370709 is an apocalyptic number.

It is an amenable number.

2640370709 is a deficient number, since it is larger than the sum of its proper divisors (13403095).

2640370709 is a wasteful number, since it uses less digits than its factorization.

2640370709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13403094.

The product of its (nonzero) digits is 63504, while the sum is 38.

The square root of 2640370709 is about 51384.5376450932. The cubic root of 2640370709 is about 1382.1493337847.

The spelling of 2640370709 in words is "two billion, six hundred forty million, three hundred seventy thousand, seven hundred nine".