204891256643 has 8 divisors (see below), whose sum is σ = 209894901216. Its totient is φ = 199887912000.

The previous prime is 204891256627. The next prime is 204891256649. The reversal of 204891256643 is 346652198402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 204891256643 - 2⁴ = 204891256627 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 204891256591 and 204891256600.

It is not an unprimeable number, because it can be changed into a prime (204891256649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2000993 + ... + 2100893.

It is an arithmetic number, because the mean of its divisors is an integer number (26236862652).

Almost surely, 2^204891256643 is an apocalyptic number.

204891256643 is a deficient number, since it is larger than the sum of its proper divisors (5003644573).

204891256643 is an equidigital number, since it uses as much as digits as its factorization.

204891256643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149965.

The product of its (nonzero) digits is 2488320, while the sum is 50.

The spelling of 204891256643 in words is "two hundred four billion, eight hundred ninety-one million, two hundred fifty-six thousand, six hundred forty-three".