638877077 has 4 divisors (see below), whose sum is σ = 641422656. Its totient is φ = 636331500.

The previous prime is 638877073. The next prime is 638877089. The reversal of 638877077 is 770778836.

638877077 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 638877077 - 2² = 638877073 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 (638877073) 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, 1272413 + ... + 1272914.

It is an arithmetic number, because the mean of its divisors is an integer number (160355664).

Almost surely, 2^638877077 is an apocalyptic number.

It is an amenable number.

638877077 is a deficient number, since it is larger than the sum of its proper divisors (2545579).

638877077 is a wasteful number, since it uses less digits than its factorization.

638877077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2545578.

The product of its (nonzero) digits is 2765952, while the sum is 53.

The square root of 638877077 is about 25276.0178232252. The cubic root of 638877077 is about 861.2695675613.

The spelling of 638877077 in words is "six hundred thirty-eight million, eight hundred seventy-seven thousand, seventy-seven".