199656901 has 8 divisors (see below), whose sum is σ = 201924504. Its totient is φ = 197395200.

The previous prime is 199656887. The next prime is 199656913. The reversal of 199656901 is 109656991.

It is a Cunningham number, because it is equal to 14130²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 63584676 + 136072225 = 7974^2 + 11665^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 199656901 - 2¹¹ = 199654853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199656931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119665 + ... + 121321.

It is an arithmetic number, because the mean of its divisors is an integer number (25240563).

Almost surely, 2^199656901 is an apocalyptic number.

It is an amenable number.

199656901 is a deficient number, since it is larger than the sum of its proper divisors (2267603).

199656901 is a wasteful number, since it uses less digits than its factorization.

199656901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2951.

The product of its (nonzero) digits is 131220, while the sum is 46.

The square root of 199656901 is about 14130.0000353857. Note that the first 4 decimals coincide. The cubic root of 199656901 is about 584.4689470470.

The spelling of 199656901 in words is "one hundred ninety-nine million, six hundred fifty-six thousand, nine hundred one".