204106611661 has 4 divisors (see below), whose sum is σ = 212980812192. Its totient is φ = 195232411132.

The previous prime is 204106611623. The next prime is 204106611733. The reversal of 204106611661 is 166116601402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 204106611661 - 2¹¹ = 204106609613 is a prime.

It is a super-2 number, since 2×204106611661² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204106671661) 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, 4437100231 + ... + 4437100276.

It is an arithmetic number, because the mean of its divisors is an integer number (53245203048).

Almost surely, 2^204106611661 is an apocalyptic number.

It is an amenable number.

204106611661 is a deficient number, since it is larger than the sum of its proper divisors (8874200531).

204106611661 is an equidigital number, since it uses as much as digits as its factorization.

204106611661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8874200530.

The product of its (nonzero) digits is 10368, while the sum is 34.

The spelling of 204106611661 in words is "two hundred four billion, one hundred six million, six hundred eleven thousand, six hundred sixty-one".