649663297920 has 768 divisors, whose sum is σ = 2819922094080. Its totient is φ = 134150307840.

The previous prime is 649663297919. The next prime is 649663297973. The reversal of 649663297920 is 29792366946.

649663297920 is a `hidden beast` number, since 6 + 496 + 6 + 32 + 97 + 9 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

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, 24622335 + ... + 24648705.

It is an arithmetic number, because the mean of its divisors is an integer number (3671773560).

Almost surely, 2^649663297920 is an apocalyptic number.

649663297920 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 649663297920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1409961047040).

649663297920 is an abundant number, since it is smaller than the sum of its proper divisors (2170258796160).

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

649663297920 is a wasteful number, since it uses less digits than its factorization.

649663297920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26463 (or 26448 counting only the distinct ones).

The product of its (nonzero) digits is 52907904, while the sum is 63.

The spelling of 649663297920 in words is "six hundred forty-nine billion, six hundred sixty-three million, two hundred ninety-seven thousand, nine hundred twenty".