638353445401 has 4 divisors (see below), whose sum is σ = 729546794752. Its totient is φ = 547160096052.

The previous prime is 638353445357. The next prime is 638353445413. The reversal of 638353445401 is 104544353836.

It is a happy number.

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 638353445401 - 2⁷ = 638353445273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638353445491) 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, 45596674665 + ... + 45596674678.

It is an arithmetic number, because the mean of its divisors is an integer number (182386698688).

Almost surely, 2^638353445401 is an apocalyptic number.

It is an amenable number.

638353445401 is a deficient number, since it is larger than the sum of its proper divisors (91193349351).

638353445401 is an equidigital number, since it uses as much as digits as its factorization.

638353445401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91193349350.

The product of its (nonzero) digits is 2073600, while the sum is 46.

The spelling of 638353445401 in words is "six hundred thirty-eight billion, three hundred fifty-three million, four hundred forty-five thousand, four hundred one".