199565661605 has 16 divisors (see below), whose sum is σ = 254391762240. Its totient is φ = 149771734272.

The previous prime is 199565661593. The next prime is 199565661623. The reversal of 199565661605 is 506166565991.

It is a happy number.

It is not a de Polignac number, because 199565661605 - 2⁶ = 199565661541 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3797735 + ... + 3849924.

It is an arithmetic number, because the mean of its divisors is an integer number (15899485140).

Almost surely, 2^199565661605 is an apocalyptic number.

It is an amenable number.

199565661605 is a deficient number, since it is larger than the sum of its proper divisors (54826100635).

199565661605 is a wasteful number, since it uses less digits than its factorization.

199565661605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7647988.

The product of its (nonzero) digits is 13122000, while the sum is 59.

The spelling of 199565661605 in words is "one hundred ninety-nine billion, five hundred sixty-five million, six hundred sixty-one thousand, six hundred five".