638878163 has 16 divisors (see below), whose sum is σ = 822220800. Its totient is φ = 481766400.

The previous prime is 638878159. The next prime is 638878171. The reversal of 638878163 is 361878836.

It is a cyclic number.

It is not a de Polignac number, because 638878163 - 2² = 638878159 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638878463) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 131438 + ... + 136211.

It is an arithmetic number, because the mean of its divisors is an integer number (51388800).

Almost surely, 2^638878163 is an apocalyptic number.

638878163 is a deficient number, since it is larger than the sum of its proper divisors (183342637).

638878163 is a wasteful number, since it uses less digits than its factorization.

638878163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267698.

The product of its digits is 1161216, while the sum is 50.

The square root of 638878163 is about 25276.0393060305. The cubic root of 638878163 is about 861.2700555729.

The spelling of 638878163 in words is "six hundred thirty-eight million, eight hundred seventy-eight thousand, one hundred sixty-three".