2638538765 has 4 divisors (see below), whose sum is σ = 3166246524. Its totient is φ = 2110831008.

The previous prime is 2638538761. The next prime is 2638538801. The reversal of 2638538765 is 5678358362.

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 386751556 + 2251787209 = 19666^2 + 47453^2 .

It is a cyclic number.

It is not a de Polignac number, because 2638538765 - 2² = 2638538761 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 (2638538761) 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, 263853872 + ... + 263853881.

It is an arithmetic number, because the mean of its divisors is an integer number (791561631).

Almost surely, 2^2638538765 is an apocalyptic number.

It is an amenable number.

2638538765 is a deficient number, since it is larger than the sum of its proper divisors (527707759).

2638538765 is an equidigital number, since it uses as much as digits as its factorization.

2638538765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 527707758.

The product of its digits is 7257600, while the sum is 53.

The square root of 2638538765 is about 51366.7087226737. The cubic root of 2638538765 is about 1381.8296051969.

The spelling of 2638538765 in words is "two billion, six hundred thirty-eight million, five hundred thirty-eight thousand, seven hundred sixty-five".