2638787864 has 8 divisors (see below), whose sum is σ = 4947727260. Its totient is φ = 1319393928.

The previous prime is 2638787863. The next prime is 2638787869. The reversal of 2638787864 is 4687878362.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2638787863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 164924234 + ... + 164924249.

Almost surely, 2^2638787864 is an apocalyptic number.

It is an amenable number.

2638787864 is a deficient number, since it is larger than the sum of its proper divisors (2308939396).

2638787864 is a wasteful number, since it uses less digits than its factorization.

2638787864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329848489 (or 329848485 counting only the distinct ones).

The product of its digits is 21676032, while the sum is 59.

The square root of 2638787864 is about 51369.1333779343. The cubic root of 2638787864 is about 1381.8730890557.

The spelling of 2638787864 in words is "two billion, six hundred thirty-eight million, seven hundred eighty-seven thousand, eight hundred sixty-four".