638801667 has 16 divisors (see below), whose sum is σ = 1081569280. Its totient is φ = 365029416.

The previous prime is 638801627. The next prime is 638801677. The reversal of 638801667 is 766108836.

638801667 is a `hidden beast` number, since 638 + 8 + 0 + 1 + 6 + 6 + 7 = 666.

It is not a de Polignac number, because 638801667 - 2⁷ = 638801539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638801627) 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 15 ways as a sum of consecutive naturals, for example, 1689763 + ... + 1690140.

It is an arithmetic number, because the mean of its divisors is an integer number (67598080).

Almost surely, 2^638801667 is an apocalyptic number.

638801667 is a deficient number, since it is larger than the sum of its proper divisors (442767613).

638801667 is a wasteful number, since it uses less digits than its factorization.

638801667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3379919 (or 3379913 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 638801667 is about 25274.5260489688. The cubic root of 638801667 is about 861.2356795120.

The spelling of 638801667 in words is "six hundred thirty-eight million, eight hundred one thousand, six hundred sixty-seven".