638253399 has 16 divisors (see below), whose sum is σ = 975473408. Its totient is φ = 363629952.

The previous prime is 638253391. The next prime is 638253419. The reversal of 638253399 is 993352836.

It is not a de Polignac number, because 638253399 - 2³ = 638253391 is a prime.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638253391) 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, 38017 + ... + 52170.

It is an arithmetic number, because the mean of its divisors is an integer number (60967088).

Almost surely, 2^638253399 is an apocalyptic number.

638253399 is a deficient number, since it is larger than the sum of its proper divisors (337220009).

638253399 is a wasteful number, since it uses less digits than its factorization.

638253399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90534.

The product of its digits is 1049760, while the sum is 48.

The square root of 638253399 is about 25263.6774639006. The cubic root of 638253399 is about 860.9892164122.

The spelling of 638253399 in words is "six hundred thirty-eight million, two hundred fifty-three thousand, three hundred ninety-nine".