2638686389 has 4 divisors (see below), whose sum is σ = 2777564640. Its totient is φ = 2499808140.

The previous prime is 2638686373. The next prime is 2638686403. The reversal of 2638686389 is 9836868362.

2638686389 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2638686389 - 2⁴ = 2638686373 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 (2638686319) 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, 69439097 + ... + 69439134.

It is an arithmetic number, because the mean of its divisors is an integer number (694391160).

Almost surely, 2^2638686389 is an apocalyptic number.

It is an amenable number.

2638686389 is a deficient number, since it is larger than the sum of its proper divisors (138878251).

2638686389 is a wasteful number, since it uses less digits than its factorization.

2638686389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138878250.

The product of its digits is 17915904, while the sum is 59.

The square root of 2638686389 is about 51368.1456644096. The cubic root of 2638686389 is about 1381.8553754467.

The spelling of 2638686389 in words is "two billion, six hundred thirty-eight million, six hundred eighty-six thousand, three hundred eighty-nine".