643798854 has 28 divisors (see below), whose sum is σ = 1447888356. Its totient is φ = 214599132.

The previous prime is 643798849. The next prime is 643798873. The reversal of 643798854 is 458897346.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 643798854.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 219324 + ... + 222239.

Almost surely, 2^643798854 is an apocalyptic number.

643798854 is an abundant number, since it is smaller than the sum of its proper divisors (804089502).

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

643798854 is an equidigital number, since it uses as much as digits as its factorization.

643798854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441583 (or 441568 counting only the distinct ones).

The product of its digits is 5806080, while the sum is 54.

The square root of 643798854 is about 25373.1916399967. The cubic root of 643798854 is about 863.4755932328.

The spelling of 643798854 in words is "six hundred forty-three million, seven hundred ninety-eight thousand, eight hundred fifty-four".