638639053 has 18 divisors (see below), whose sum is σ = 708477966. Its totient is φ = 572270832.

The previous prime is 638639047. The next prime is 638639117. The reversal of 638639053 is 350936836.

638639053 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 442134729 + 196504324 = 21027^2 + 14018^2 .

It is not a de Polignac number, because 638639053 - 2⁵ = 638639021 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638639003) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3917950 + ... + 3918112.

It is an arithmetic number, because the mean of its divisors is an integer number (39359887).

Almost surely, 2^638639053 is an apocalyptic number.

It is an amenable number.

638639053 is a deficient number, since it is larger than the sum of its proper divisors (69838913).

638639053 is an equidigital number, since it uses as much as digits as its factorization.

638639053 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425 (or 219 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 43.

The square root of 638639053 is about 25271.3088897271. The cubic root of 638639053 is about 861.1625943009.

The spelling of 638639053 in words is "six hundred thirty-eight million, six hundred thirty-nine thousand, fifty-three".