643687614 has 64 divisors (see below), whose sum is σ = 1498798080. Its totient is φ = 204383520.

The previous prime is 643687613. The next prime is 643687651. The reversal of 643687614 is 416786346.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 643687614.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643687613) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 343099 + ... + 344969.

It is an arithmetic number, because the mean of its divisors is an integer number (23418720).

Almost surely, 2^643687614 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643687614, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (749399040).

643687614 is an abundant number, since it is smaller than the sum of its proper divisors (855110466).

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

643687614 is a wasteful number, since it uses less digits than its factorization.

643687614 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2182 (or 2176 counting only the distinct ones).

The product of its digits is 580608, while the sum is 45.

The square root of 643687614 is about 25370.9994678964. Note that the first 3 decimals coincide. The cubic root of 643687614 is about 863.4258579482.

The spelling of 643687614 in words is "six hundred forty-three million, six hundred eighty-seven thousand, six hundred fourteen".