638807697 has 24 divisors (see below), whose sum is σ = 1010232288. Its totient is φ = 385761600.

The previous prime is 638807671. The next prime is 638807707. The reversal of 638807697 is 796708836.

It is not a de Polignac number, because 638807697 - 2¹⁰ = 638806673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638808697) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16338 + ... + 39300.

It is an arithmetic number, because the mean of its divisors is an integer number (42093012).

Almost surely, 2^638807697 is an apocalyptic number.

It is an amenable number.

638807697 is a deficient number, since it is larger than the sum of its proper divisors (371424591).

638807697 is a wasteful number, since it uses less digits than its factorization.

638807697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23261 (or 23258 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 54.

The square root of 638807697 is about 25274.6453387580. The cubic root of 638807697 is about 861.2383893958.

The spelling of 638807697 in words is "six hundred thirty-eight million, eight hundred seven thousand, six hundred ninety-seven".