649756640 has 48 divisors (see below), whose sum is σ = 1653136128. Its totient is φ = 239909376.

The previous prime is 649756637. The next prime is 649756697. The reversal of 649756640 is 46657946.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154112 + ... + 158271.

It is an arithmetic number, because the mean of its divisors is an integer number (34440336).

Almost surely, 2^649756640 is an apocalyptic number.

It is an amenable number.

649756640 is an abundant number, since it is smaller than the sum of its proper divisors (1003379488).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

649756640 is a wasteful number, since it uses less digits than its factorization.

649756640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312411 (or 312403 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 47.

The square root of 649756640 is about 25490.3244388925. The cubic root of 649756640 is about 866.1309852060.

The spelling of 649756640 in words is "six hundred forty-nine million, seven hundred fifty-six thousand, six hundred forty".