643078792 has 8 divisors (see below), whose sum is σ = 1205772750. Its totient is φ = 321539392.

The previous prime is 643078783. The next prime is 643078811. The reversal of 643078792 is 297870346.

It can be written as a sum of positive squares in only one way, i.e., 619711236 + 23367556 = 24894^2 + 4834^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40192417 + ... + 40192432.

Almost surely, 2^643078792 is an apocalyptic number.

It is an amenable number.

643078792 is a deficient number, since it is larger than the sum of its proper divisors (562693958).

643078792 is a wasteful number, since it uses less digits than its factorization.

643078792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80384855 (or 80384851 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 46.

The square root of 643078792 is about 25358.9982451989. The cubic root of 643078792 is about 863.1535527355.

The spelling of 643078792 in words is "six hundred forty-three million, seventy-eight thousand, seven hundred ninety-two".