649031640 has 256 divisors, whose sum is σ = 2155507200. Its totient is φ = 155750400.

The previous prime is 649031623. The next prime is 649031651. The reversal of 649031640 is 46130946.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4954375 + ... + 4954505.

It is an arithmetic number, because the mean of its divisors is an integer number (8419950).

Almost surely, 2^649031640 is an apocalyptic number.

649031640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 649031640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1077753600).

649031640 is an abundant number, since it is smaller than the sum of its proper divisors (1506475560).

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

649031640 is a wasteful number, since it uses less digits than its factorization.

649031640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258 (or 254 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 33.

The square root of 649031640 is about 25476.0993874651. The cubic root of 649031640 is about 865.8087216463.

The spelling of 649031640 in words is "six hundred forty-nine million, thirty-one thousand, six hundred forty".