638073865 has 48 divisors (see below), whose sum is σ = 952361280. Its totient is φ = 405699840.

The previous prime is 638073851. The next prime is 638073881. The reversal of 638073865 is 568370836.

It is not a de Polignac number, because 638073865 - 2²¹ = 635976713 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 174799 + ... + 178411.

It is an arithmetic number, because the mean of its divisors is an integer number (19840860).

Almost surely, 2^638073865 is an apocalyptic number.

638073865 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

638073865 is a deficient number, since it is larger than the sum of its proper divisors (314287415).

638073865 is a wasteful number, since it uses less digits than its factorization.

638073865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3674 (or 3661 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 46.

The square root of 638073865 is about 25260.1240099885. The cubic root of 638073865 is about 860.9084797569.

The spelling of 638073865 in words is "six hundred thirty-eight million, seventy-three thousand, eight hundred sixty-five".