638794955 has 16 divisors (see below), whose sum is σ = 789100704. Its totient is φ = 496204800.

The previous prime is 638794927. The next prime is 638794957. The reversal of 638794955 is 559497836.

It is a happy number.

638794955 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 638794955 - 2²⁰ = 637746379 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 638794955.

It is not an unprimeable number, because it can be changed into a prime (638794957) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13280 + ... + 38130.

It is an arithmetic number, because the mean of its divisors is an integer number (49318794).

Almost surely, 2^638794955 is an apocalyptic number.

638794955 is a deficient number, since it is larger than the sum of its proper divisors (150305749).

638794955 is a wasteful number, since it uses less digits than its factorization.

638794955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25006.

The product of its digits is 8164800, while the sum is 56.

The square root of 638794955 is about 25274.3932667038. The cubic root of 638794955 is about 861.2326631172.

The spelling of 638794955 in words is "six hundred thirty-eight million, seven hundred ninety-four thousand, nine hundred fifty-five".