199801791 has 24 divisors (see below), whose sum is σ = 330266144. Its totient is φ = 114022080.

The previous prime is 199801787. The next prime is 199801801. The reversal of 199801791 is 197108991.

It is not a de Polignac number, because 199801791 - 2² = 199801787 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 (199801751) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 61221 + ... + 64401.

Almost surely, 2^199801791 is an apocalyptic number.

199801791 is a deficient number, since it is larger than the sum of its proper divisors (130464353).

199801791 is a wasteful number, since it uses less digits than its factorization.

199801791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4191 (or 4188 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 45.

The square root of 199801791 is about 14135.1261402224. The cubic root of 199801791 is about 584.6102949105.

The spelling of 199801791 in words is "one hundred ninety-nine million, eight hundred one thousand, seven hundred ninety-one".