638253401 has 4 divisors (see below), whose sum is σ = 650295972. Its totient is φ = 626210832.

The previous prime is 638253391. The next prime is 638253419. The reversal of 638253401 is 104352836.

638253401 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.

It can be written as a sum of positive squares in 2 ways, for example, as 306285001 + 331968400 = 17501^2 + 18220^2 .

It is a cyclic number.

It is not a de Polignac number, because 638253401 - 2⁶ = 638253337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638253481) 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, 6021206 + ... + 6021311.

It is an arithmetic number, because the mean of its divisors is an integer number (162573993).

Almost surely, 2^638253401 is an apocalyptic number.

It is an amenable number.

638253401 is a deficient number, since it is larger than the sum of its proper divisors (12042571).

638253401 is a wasteful number, since it uses less digits than its factorization.

638253401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12042570.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 638253401 is about 25263.6775034831. The cubic root of 638253401 is about 860.9892173115.

The spelling of 638253401 in words is "six hundred thirty-eight million, two hundred fifty-three thousand, four hundred one".