649257808 has 10 divisors (see below), whose sum is σ = 1257937034. Its totient is φ = 324628896.

The previous prime is 649257803. The next prime is 649257809. The reversal of 649257808 is 808752946.

It can be written as a sum of positive squares in only one way, i.e., 646786624 + 2471184 = 25432^2 + 1572^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649257803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20289291 + ... + 20289322.

Almost surely, 2^649257808 is an apocalyptic number.

It is an amenable number.

649257808 is a deficient number, since it is larger than the sum of its proper divisors (608679226).

649257808 is a wasteful number, since it uses less digits than its factorization.

649257808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40578621 (or 40578615 counting only the distinct ones).

The product of its (nonzero) digits is 967680, while the sum is 49.

The square root of 649257808 is about 25480.5378279188. The cubic root of 649257808 is about 865.9092793971.

The spelling of 649257808 in words is "six hundred forty-nine million, two hundred fifty-seven thousand, eight hundred eight".