638069621 has 24 divisors (see below), whose sum is σ = 773959680. Its totient is φ = 523908000.

The previous prime is 638069617. The next prime is 638069623. The reversal of 638069621 is 126960836.

It is not a de Polignac number, because 638069621 - 2² = 638069617 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638069623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 151340 + ... + 155498.

It is an arithmetic number, because the mean of its divisors is an integer number (32248320).

Almost surely, 2^638069621 is an apocalyptic number.

It is an amenable number.

638069621 is a deficient number, since it is larger than the sum of its proper divisors (135890059).

638069621 is a wasteful number, since it uses less digits than its factorization.

638069621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4305 (or 4298 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 41.

The square root of 638069621 is about 25260.0400039272. The cubic root of 638069621 is about 860.9065710418.

The spelling of 638069621 in words is "six hundred thirty-eight million, sixty-nine thousand, six hundred twenty-one".