639116649 has 20 divisors (see below), whose sum is σ = 1010892564. Its totient is φ = 401013504.

The previous prime is 639116633. The next prime is 639116657. The reversal of 639116649 is 946611936.

639116649 is a `hidden beast` number, since 639 + 1 + 1 + 6 + 6 + 4 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 382476249 + 256640400 = 19557^2 + 16020^2 .

It is not a de Polignac number, because 639116649 - 2⁴ = 639116633 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (639116629) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 230692 + ... + 233445.

Almost surely, 2^639116649 is an apocalyptic number.

It is an amenable number.

639116649 is a deficient number, since it is larger than the sum of its proper divisors (371775915).

639116649 is a wasteful number, since it uses less digits than its factorization.

639116649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 464166 (or 464157 counting only the distinct ones).

The product of its digits is 209952, while the sum is 45.

The square root of 639116649 is about 25280.7564958013. The cubic root of 639116649 is about 861.3772097011.

The spelling of 639116649 in words is "six hundred thirty-nine million, one hundred sixteen thousand, six hundred forty-nine".