205061661 has 48 divisors (see below), whose sum is σ = 358858240. Its totient is φ = 110224800.

The previous prime is 205061653. The next prime is 205061663. The reversal of 205061661 is 166160502.

It is a happy number.

It is not a de Polignac number, because 205061661 - 2³ = 205061653 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 (205061663) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 194586 + ... + 195636.

Almost surely, 2^205061661 is an apocalyptic number.

205061661 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

205061661 is a deficient number, since it is larger than the sum of its proper divisors (153796579).

205061661 is a wasteful number, since it uses less digits than its factorization.

205061661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1246 (or 1243 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 205061661 is about 14319.9741969041. The cubic root of 205061661 is about 589.6959661164.

The spelling of 205061661 in words is "two hundred five million, sixty-one thousand, six hundred sixty-one".