204240243997 has 2 divisors, whose sum is σ = 204240243998. Its totient is φ = 204240243996.

The previous prime is 204240243967. The next prime is 204240244121. The reversal of 204240243997 is 799342042402.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126011510361 + 78228733636 = 354981^2 + 279694^2 .

It is a cyclic number.

It is not a de Polignac number, because 204240243997 - 2¹⁵ = 204240211229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (204240243967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102120121998 + 102120121999.

It is an arithmetic number, because the mean of its divisors is an integer number (102120121999).

Almost surely, 2^204240243997 is an apocalyptic number.

It is an amenable number.

204240243997 is a deficient number, since it is larger than the sum of its proper divisors (1).

204240243997 is an equidigital number, since it uses as much as digits as its factorization.

204240243997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 870912, while the sum is 46.

The spelling of 204240243997 in words is "two hundred four billion, two hundred forty million, two hundred forty-three thousand, nine hundred ninety-seven".