638507894 has 8 divisors (see below), whose sum is σ = 968523480. Its totient is φ = 315666736.

The previous prime is 638507887. The next prime is 638507911. The reversal of 638507894 is 498705836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1793384 + ... + 1793739.

It is an arithmetic number, because the mean of its divisors is an integer number (121065435).

Almost surely, 2^638507894 is an apocalyptic number.

638507894 is a deficient number, since it is larger than the sum of its proper divisors (330015586).

638507894 is a wasteful number, since it uses less digits than its factorization.

638507894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3587214.

The product of its (nonzero) digits is 1451520, while the sum is 50.

The square root of 638507894 is about 25268.7137385345. The cubic root of 638507894 is about 861.1036371809.

The spelling of 638507894 in words is "six hundred thirty-eight million, five hundred seven thousand, eight hundred ninety-four".