205165649 has 4 divisors (see below), whose sum is σ = 220947636. Its totient is φ = 189383664.

The previous prime is 205165637. The next prime is 205165711. The reversal of 205165649 is 946561502.

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 10758400 + 194407249 = 3280^2 + 13943^2 .

It is a cyclic number.

It is not a de Polignac number, because 205165649 - 2²⁴ = 188388433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205165619) 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, 7890974 + ... + 7890999.

It is an arithmetic number, because the mean of its divisors is an integer number (55236909).

Almost surely, 2^205165649 is an apocalyptic number.

It is an amenable number.

205165649 is a deficient number, since it is larger than the sum of its proper divisors (15781987).

205165649 is a wasteful number, since it uses less digits than its factorization.

205165649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15781986.

The product of its (nonzero) digits is 64800, while the sum is 38.

The square root of 205165649 is about 14323.6046091757. The cubic root of 205165649 is about 589.7956287272.

The spelling of 205165649 in words is "two hundred five million, one hundred sixty-five thousand, six hundred forty-nine".