646957945041408 has 5760 divisors, whose sum is σ = 2809763299639296. Its totient is φ = 145828292198400.

The previous prime is 646957945041379. The next prime is 646957945041437. The reversal of 646957945041408 is 804140549759646.

646957945041408 is a `hidden beast` number, since 6 + 4 + 6 + 9 + 5 + 79 + 4 + 504 + 1 + 40 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (646957945041379) and next prime (646957945041437).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 575 ways as a sum of consecutive naturals, for example, 999934999741 + ... + 999935000387.

Almost surely, 2^{646957945041408} 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 646957945041408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1404881649819648).

646957945041408 is an abundant number, since it is smaller than the sum of its proper divisors (2162805354597888).

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

646957945041408 is a wasteful number, since it uses less digits than its factorization.

646957945041408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 786 (or 751 counting only the distinct ones).

The product of its (nonzero) digits is 1045094400, while the sum is 72.

The spelling of 646957945041408 in words is "six hundred forty-six trillion, nine hundred fifty-seven billion, nine hundred forty-five million, forty-one thousand, four hundred eight".