638976805 has 16 divisors (see below), whose sum is σ = 792336384. Its totient is φ = 494173440.

The previous prime is 638976799. The next prime is 638976809. The reversal of 638976805 is 508679836.

It is not a de Polignac number, because 638976805 - 2¹⁷ = 638845733 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 (638976809) 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 15 ways as a sum of consecutive naturals, for example, 219117 + ... + 222013.

It is an arithmetic number, because the mean of its divisors is an integer number (49521024).

Almost surely, 2^638976805 is an apocalyptic number.

It is an amenable number.

638976805 is a deficient number, since it is larger than the sum of its proper divisors (153359579).

638976805 is a wasteful number, since it uses less digits than its factorization.

638976805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4356.

The product of its (nonzero) digits is 2177280, while the sum is 52.

The square root of 638976805 is about 25277.9905253562. The cubic root of 638976805 is about 861.3143796364.

The spelling of 638976805 in words is "six hundred thirty-eight million, nine hundred seventy-six thousand, eight hundred five".