639199898 has 8 divisors (see below), whose sum is σ = 1015199892. Its totient is φ = 300799936.

The previous prime is 639199889. The next prime is 639199903. The reversal of 639199898 is 898991936.

It can be written as a sum of positive squares in 2 ways, for example, as 496086529 + 143113369 = 22273^2 + 11963^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 639199898.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9399965 + ... + 9400032.

Almost surely, 2^639199898 is an apocalyptic number.

639199898 is a deficient number, since it is larger than the sum of its proper divisors (375999994).

639199898 is a wasteful number, since it uses less digits than its factorization.

639199898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18800016.

The product of its digits is 7558272, while the sum is 62.

The square root of 639199898 is about 25282.4029316835. The cubic root of 639199898 is about 861.4146080270.

The spelling of 639199898 in words is "six hundred thirty-nine million, one hundred ninety-nine thousand, eight hundred ninety-eight".