649657386368640 has 768 divisors, whose sum is σ = 2492711099424000. Its totient is φ = 159836295610368.

The previous prime is 649657386368587. The next prime is 649657386368651. The reversal of 649657386368640 is 46863683756946.

649657386368640 is a `hidden beast` number, since 6 + 4 + 9 + 6 + 573 + 8 + 6 + 36 + 8 + 6 + 4 + 0 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 649657386368640.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5995362781 + ... + 5995471139.

It is an arithmetic number, because the mean of its divisors is an integer number (3245717577375).

Almost surely, 2^{649657386368640} is an apocalyptic number.

649657386368640 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 649657386368640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1246355549712000).

649657386368640 is an abundant number, since it is smaller than the sum of its proper divisors (1843053713055360).

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

649657386368640 is a wasteful number, since it uses less digits than its factorization.

649657386368640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110466 (or 110435 counting only the distinct ones).

The product of its (nonzero) digits is 22574039040, while the sum is 81.

The spelling of 649657386368640 in words is "six hundred forty-nine trillion, six hundred fifty-seven billion, three hundred eighty-six million, three hundred sixty-eight thousand, six hundred forty".