646999562234880 has 1760 divisors, whose sum is σ = 2474354609717760. Its totient is φ = 161386463232000.

The previous prime is 646999562234813. The next prime is 646999562234897. The reversal of 646999562234880 is 88432265999646.

646999562234880 is a `hidden beast` number, since 6 + 4 + 6 + 9 + 9 + 9 + 562 + 2 + 3 + 48 + 8 + 0 = 666.

It is a super-2 number, since 2×646999562234880² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a self number, because there is not a number n which added to its sum of digits gives 646999562234880.

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 159 ways as a sum of consecutive naturals, for example, 57454888450 + ... + 57454899710.

It is an arithmetic number, because the mean of its divisors is an integer number (1405883300976).

Almost surely, 2^{646999562234880} is an apocalyptic number.

646999562234880 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 646999562234880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1237177304858880).

646999562234880 is an abundant number, since it is smaller than the sum of its proper divisors (1827355047482880).

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

646999562234880 is a wasteful number, since it uses less digits than its factorization.

646999562234880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11479 (or 11452 counting only the distinct ones).

The product of its (nonzero) digits is 9674588160, while the sum is 81.

The spelling of 646999562234880 in words is "six hundred forty-six trillion, nine hundred ninety-nine billion, five hundred sixty-two million, two hundred thirty-four thousand, eight hundred eighty".