640278196766208 has 2880 divisors, whose sum is σ = 2620642664420352. Its totient is φ = 145854144184320.

The previous prime is 640278196766189. The next prime is 640278196766297. The reversal of 640278196766208 is 802667691872046.

640278196766208 is a `hidden beast` number, since 6 + 4 + 0 + 278 + 1 + 96 + 7 + 66 + 208 = 666.

It is a super-2 number, since 2×640278196766208² (a number of 30 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 216529655866 + ... + 216529658822.

Almost surely, 2^{640278196766208} 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 640278196766208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1310321332210176).

640278196766208 is an abundant number, since it is smaller than the sum of its proper divisors (1980364467654144).

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

640278196766208 is a wasteful number, since it uses less digits than its factorization.

640278196766208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3205 (or 3173 counting only the distinct ones).

The product of its (nonzero) digits is 585252864, while the sum is 72.

The spelling of 640278196766208 in words is "six hundred forty trillion, two hundred seventy-eight billion, one hundred ninety-six million, seven hundred sixty-six thousand, two hundred eight".