199925909 has 4 divisors (see below), whose sum is σ = 199954380. Its totient is φ = 199897440.

The previous prime is 199925897. The next prime is 199925927. The reversal of 199925909 is 909529991.

199925909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 103591684 + 96334225 = 10178^2 + 9815^2 .

It is a cyclic number.

It is not a de Polignac number, because 199925909 - 2⁸ = 199925653 is a prime.

It is a super-3 number, since 3×199925909³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199925309) 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, 4649 + ... + 20529.

It is an arithmetic number, because the mean of its divisors is an integer number (49988595).

Almost surely, 2^199925909 is an apocalyptic number.

It is an amenable number.

199925909 is a deficient number, since it is larger than the sum of its proper divisors (28471).

199925909 is a wasteful number, since it uses less digits than its factorization.

199925909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28470.

The product of its (nonzero) digits is 590490, while the sum is 53.

The square root of 199925909 is about 14139.5158686569. The cubic root of 199925909 is about 584.7313242573.

The spelling of 199925909 in words is "one hundred ninety-nine million, nine hundred twenty-five thousand, nine hundred nine".