643362784 has 12 divisors (see below), whose sum is σ = 1266620544. Its totient is φ = 321681376.

The previous prime is 643362763. The next prime is 643362787. The reversal of 643362784 is 487263346.

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 643362784.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643362787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10052512 + ... + 10052575.

It is an arithmetic number, because the mean of its divisors is an integer number (105551712).

Almost surely, 2^643362784 is an apocalyptic number.

It is an amenable number.

643362784 is a deficient number, since it is larger than the sum of its proper divisors (623257760).

643362784 is a wasteful number, since it uses less digits than its factorization.

643362784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20105097 (or 20105089 counting only the distinct ones).

The product of its digits is 580608, while the sum is 43.

The square root of 643362784 is about 25364.5970596814. The cubic root of 643362784 is about 863.2805939999.

The spelling of 643362784 in words is "six hundred forty-three million, three hundred sixty-two thousand, seven hundred eighty-four".