205605641 has 4 divisors (see below), whose sum is σ = 205646484. Its totient is φ = 205564800.

The previous prime is 205605581. The next prime is 205605689. The reversal of 205605641 is 146506502.

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 129846025 + 75759616 = 11395^2 + 8704^2 .

It is a cyclic number.

It is not a de Polignac number, because 205605641 - 2¹⁸ = 205343497 is a prime.

It is a super-2 number, since 2×205605641² = 84547359222041762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205607641) 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, 11600 + ... + 23361.

It is an arithmetic number, because the mean of its divisors is an integer number (51411621).

Almost surely, 2^205605641 is an apocalyptic number.

It is an amenable number.

205605641 is a deficient number, since it is larger than the sum of its proper divisors (40843).

205605641 is an equidigital number, since it uses as much as digits as its factorization.

205605641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40842.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 205605641 is about 14338.9553664136. The cubic root of 205605641 is about 590.2169469338.

The spelling of 205605641 in words is "two hundred five million, six hundred five thousand, six hundred forty-one".