199687865 has 24 divisors (see below), whose sum is σ = 274759128. Its totient is φ = 138777600.

The previous prime is 199687861. The next prime is 199687867. The reversal of 199687865 is 568786991.

It can be written as a sum of positive squares in 12 ways, for example, as 52113961 + 147573904 = 7219^2 + 12148^2 .

It is not a de Polignac number, because 199687865 - 2² = 199687861 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199687861) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7415 + ... + 21315.

It is an arithmetic number, because the mean of its divisors is an integer number (11448297).

Almost surely, 2^199687865 is an apocalyptic number.

It is an amenable number.

199687865 is a deficient number, since it is larger than the sum of its proper divisors (75071263).

199687865 is a wasteful number, since it uses less digits than its factorization.

199687865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13949 (or 13936 counting only the distinct ones).

The product of its digits is 6531840, while the sum is 59.

The square root of 199687865 is about 14131.0956758491. The cubic root of 199687865 is about 584.4991598119.

The spelling of 199687865 in words is "one hundred ninety-nine million, six hundred eighty-seven thousand, eight hundred sixty-five".