638022667 has 4 divisors (see below), whose sum is σ = 638079120. Its totient is φ = 637966216.

The previous prime is 638022659. The next prime is 638022683. The reversal of 638022667 is 766220836.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 638022667 - 2³ = 638022659 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638022367) 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 3 ways as a sum of consecutive naturals, for example, 4783 + ... + 36040.

It is an arithmetic number, because the mean of its divisors is an integer number (159519780).

Almost surely, 2^638022667 is an apocalyptic number.

638022667 is a deficient number, since it is larger than the sum of its proper divisors (56453).

638022667 is a wasteful number, since it uses less digits than its factorization.

638022667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56452.

The product of its (nonzero) digits is 145152, while the sum is 40.

The square root of 638022667 is about 25259.1105742067. The cubic root of 638022667 is about 860.8854531798.

The spelling of 638022667 in words is "six hundred thirty-eight million, twenty-two thousand, six hundred sixty-seven".