199685864 has 16 divisors (see below), whose sum is σ = 427898400. Its totient is φ = 85579632.

The previous prime is 199685833. The next prime is 199685869. The reversal of 199685864 is 468586991.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (56), and also a Moran number because the ratio is a prime number: 3565819 = 199685864 / (1 + 9 + 9 + 6 + 8 + 5 + 8 + 6 + 4).

It is not an unprimeable number, because it can be changed into a prime (199685869) 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, 1782854 + ... + 1782965.

It is an arithmetic number, because the mean of its divisors is an integer number (26743650).

Almost surely, 2^199685864 is an apocalyptic number.

199685864 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

199685864 is an abundant number, since it is smaller than the sum of its proper divisors (228212536).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

199685864 is a wasteful number, since it uses less digits than its factorization.

199685864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3565832 (or 3565828 counting only the distinct ones).

The product of its digits is 3732480, while the sum is 56.

The square root of 199685864 is about 14131.0248743677. The cubic root of 199685864 is about 584.4972074537.

The spelling of 199685864 in words is "one hundred ninety-nine million, six hundred eighty-five thousand, eight hundred sixty-four".