649358640 has 320 divisors, whose sum is σ = 2598405120. Its totient is φ = 145981440.

The previous prime is 649358623. The next prime is 649358663. The reversal of 649358640 is 46853946.

649358640 is a `hidden beast` number, since 64 + 9 + 3 + 586 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1012720 + ... + 1013360.

It is an arithmetic number, because the mean of its divisors is an integer number (8120016).

Almost surely, 2^649358640 is an apocalyptic number.

649358640 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 649358640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1299202560).

649358640 is an abundant number, since it is smaller than the sum of its proper divisors (1949046480).

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

649358640 is a wasteful number, since it uses less digits than its factorization.

649358640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 737 (or 725 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The square root of 649358640 is about 25482.5163592609. The cubic root of 649358640 is about 865.9541033196.

The spelling of 649358640 in words is "six hundred forty-nine million, three hundred fifty-eight thousand, six hundred forty".