649638736 has 20 divisors (see below), whose sum is σ = 1261163700. Its totient is φ = 324177152.

The previous prime is 649638713. The next prime is 649638763. The reversal of 649638736 is 637836946.

It can be written as a sum of positive squares in 2 ways, for example, as 571210000 + 78428736 = 23900^2 + 8856^2 .

It is a congruent number.

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, 31741 + ... + 48028.

It is an arithmetic number, because the mean of its divisors is an integer number (63058185).

Almost surely, 2^649638736 is an apocalyptic number.

It is an amenable number.

649638736 is a deficient number, since it is larger than the sum of its proper divisors (611524964).

649638736 is a wasteful number, since it uses less digits than its factorization.

649638736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80286 (or 80280 counting only the distinct ones).

The product of its digits is 3919104, while the sum is 52.

The square root of 649638736 is about 25488.0116133056. The cubic root of 649638736 is about 866.0785930339.

The spelling of 649638736 in words is "six hundred forty-nine million, six hundred thirty-eight thousand, seven hundred thirty-six".