199659999 has 32 divisors (see below), whose sum is σ = 349378560. Its totient is φ = 98258400.

The previous prime is 199659997. The next prime is 199660003. The reversal of 199659999 is 999956991.

It is not a de Polignac number, because 199659999 - 2¹ = 199659997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199659991) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18357 + ... + 27134.

It is an arithmetic number, because the mean of its divisors is an integer number (10918080).

Almost surely, 2^199659999 is an apocalyptic number.

199659999 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

199659999 is a deficient number, since it is larger than the sum of its proper divisors (149718561).

199659999 is a wasteful number, since it uses less digits than its factorization.

199659999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45531.

The product of its digits is 15943230, while the sum is 66.

The square root of 199659999 is about 14130.1096598717. The cubic root of 199659999 is about 584.4719700253.

The spelling of 199659999 in words is "one hundred ninety-nine million, six hundred fifty-nine thousand, nine hundred ninety-nine".