199956861 has 12 divisors (see below), whose sum is σ = 311044188. Its totient is φ = 123050304.

The previous prime is 199956857. The next prime is 199956881. The reversal of 199956861 is 168659991.

199956861 is a `hidden beast` number, since 19 + 9 + 9 + 568 + 61 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 134444025 + 65512836 = 11595^2 + 8094^2 .

It is not a de Polignac number, because 199956861 - 2² = 199956857 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 199956798 and 199956807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199956811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 854400 + ... + 854633.

It is an arithmetic number, because the mean of its divisors is an integer number (25920349).

Almost surely, 2^199956861 is an apocalyptic number.

It is an amenable number.

199956861 is a deficient number, since it is larger than the sum of its proper divisors (111087327).

199956861 is a wasteful number, since it uses less digits than its factorization.

199956861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1709052 (or 1709049 counting only the distinct ones).

The product of its digits is 1049760, while the sum is 54.

The square root of 199956861 is about 14140.6103475062. The cubic root of 199956861 is about 584.7614982187.

The spelling of 199956861 in words is "one hundred ninety-nine million, nine hundred fifty-six thousand, eight hundred sixty-one".