643683697488 has 160 divisors (see below), whose sum is σ = 1994991062400. Its totient is φ = 197533292544.

The previous prime is 643683697477. The next prime is 643683697499. The reversal of 643683697488 is 884796386346.

643683697488 is a `hidden beast` number, since 6 + 4 + 3 + 6 + 83 + 69 + 7 + 488 = 666.

It is an interprime number because it is at equal distance from previous prime (643683697477) and next prime (643683697499).

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 31 ways as a sum of consecutive naturals, for example, 1977256 + ... + 2279672.

It is an arithmetic number, because the mean of its divisors is an integer number (12468694140).

Almost surely, 2^643683697488 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 643683697488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (997495531200).

643683697488 is an abundant number, since it is smaller than the sum of its proper divisors (1351307364912).

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

643683697488 is a wasteful number, since it uses less digits than its factorization.

643683697488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302826 (or 302814 counting only the distinct ones).

The product of its digits is 1003290624, while the sum is 72.

The spelling of 643683697488 in words is "six hundred forty-three billion, six hundred eighty-three million, six hundred ninety-seven thousand, four hundred eighty-eight".