199999864 has 8 divisors (see below), whose sum is σ = 374999760. Its totient is φ = 99999928.

The previous prime is 199999853. The next prime is 199999889. The reversal of 199999864 is 468999991.

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 199999796 and 199999805.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12499984 + ... + 12499999.

It is an arithmetic number, because the mean of its divisors is an integer number (46874970).

Almost surely, 2^199999864 is an apocalyptic number.

It is an amenable number.

199999864 is a deficient number, since it is larger than the sum of its proper divisors (174999896).

199999864 is a wasteful number, since it uses less digits than its factorization.

199999864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24999989 (or 24999985 counting only the distinct ones).

The product of its digits is 11337408, while the sum is 64.

The square root of 199999864 is about 14142.1308154040. The cubic root of 199999864 is about 584.8034150871.

The spelling of 199999864 in words is "one hundred ninety-nine million, nine hundred ninety-nine thousand, eight hundred sixty-four".