204723994243 has 4 divisors (see below), whose sum is σ = 205795847808. Its totient is φ = 203652140680.

The previous prime is 204723994231. The next prime is 204723994247. The reversal of 204723994243 is 342499327402.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204723994243 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (204723994247) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 535926496 + ... + 535926877.

It is an arithmetic number, because the mean of its divisors is an integer number (51448961952).

Almost surely, 2^204723994243 is an apocalyptic number.

204723994243 is a deficient number, since it is larger than the sum of its proper divisors (1071853565).

204723994243 is a wasteful number, since it uses less digits than its factorization.

204723994243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1071853564.

The product of its (nonzero) digits is 2612736, while the sum is 49.

The spelling of 204723994243 in words is "two hundred four billion, seven hundred twenty-three million, nine hundred ninety-four thousand, two hundred forty-three".