204028845661 has 4 divisors (see below), whose sum is σ = 204268036252. Its totient is φ = 203789655072.

The previous prime is 204028845641. The next prime is 204028845667. The reversal of 204028845661 is 166548820402.

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

It can be written as a sum of positive squares in 2 ways, for example, as 81899564761 + 122129280900 = 286181^2 + 349470^2 .

It is a cyclic number.

It is not a de Polignac number, because 204028845661 - 2¹⁵ = 204028812893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204028845667) 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, 119594016 + ... + 119595721.

It is an arithmetic number, because the mean of its divisors is an integer number (51067009063).

Almost surely, 2^204028845661 is an apocalyptic number.

It is an amenable number.

204028845661 is a deficient number, since it is larger than the sum of its proper divisors (239190591).

204028845661 is an equidigital number, since it uses as much as digits as its factorization.

204028845661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239190590.

The product of its (nonzero) digits is 737280, while the sum is 46.

The spelling of 204028845661 in words is "two hundred four billion, twenty-eight million, eight hundred forty-five thousand, six hundred sixty-one".