199709478925 has 24 divisors (see below), whose sum is σ = 270197295552. Its totient is φ = 145219152000.

The previous prime is 199709478869. The next prime is 199709478931. The reversal of 199709478925 is 529874907991.

It is not a de Polignac number, because 199709478925 - 2¹⁹ = 199708954637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1692192 + ... + 1806358.

It is an arithmetic number, because the mean of its divisors is an integer number (11258220648).

Almost surely, 2^199709478925 is an apocalyptic number.

It is an amenable number.

199709478925 is a deficient number, since it is larger than the sum of its proper divisors (70487816627).

199709478925 is a wasteful number, since it uses less digits than its factorization.

199709478925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120549 (or 120544 counting only the distinct ones).

The product of its (nonzero) digits is 102876480, while the sum is 70.

The spelling of 199709478925 in words is "one hundred ninety-nine billion, seven hundred nine million, four hundred seventy-eight thousand, nine hundred twenty-five".