638894913 has 8 divisors (see below), whose sum is σ = 867932928. Its totient is φ = 417893424.

The previous prime is 638894863. The next prime is 638894917. The reversal of 638894913 is 319498836.

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

It is not a de Polignac number, because 638894913 - 2¹⁶ = 638829377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638894917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2008945 + ... + 2009262.

It is an arithmetic number, because the mean of its divisors is an integer number (108491616).

Almost surely, 2^638894913 is an apocalyptic number.

It is an amenable number.

638894913 is a deficient number, since it is larger than the sum of its proper divisors (229038015).

638894913 is a wasteful number, since it uses less digits than its factorization.

638894913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4018263.

The product of its digits is 1119744, while the sum is 51.

The square root of 638894913 is about 25276.3706453280. The cubic root of 638894913 is about 861.2775823848.

The spelling of 638894913 in words is "six hundred thirty-eight million, eight hundred ninety-four thousand, nine hundred thirteen".