649515718656 has 672 divisors, whose sum is σ = 2343189139200. Its totient is φ = 175755018240.

The previous prime is 649515718601. The next prime is 649515718661. The reversal of 649515718656 is 656817515946.

649515718656 is a `hidden beast` number, since 6 + 4 + 9 + 5 + 1 + 571 + 8 + 6 + 56 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

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

It is a junction number, because it is equal to n+sod(n) for n = 649515718593 and 649515718602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 198566301 + ... + 198569571.

It is an arithmetic number, because the mean of its divisors is an integer number (3486888600).

Almost surely, 2^649515718656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 649515718656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1171594569600).

649515718656 is an abundant number, since it is smaller than the sum of its proper divisors (1693673420544).

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

649515718656 is an equidigital number, since it uses as much as digits as its factorization.

649515718656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3337 (or 3302 counting only the distinct ones).

The product of its digits is 54432000, while the sum is 63.

The spelling of 649515718656 in words is "six hundred forty-nine billion, five hundred fifteen million, seven hundred eighteen thousand, six hundred fifty-six".