199057391 has 4 divisors (see below), whose sum is σ = 214369512. Its totient is φ = 183745272.

The previous prime is 199057381. The next prime is 199057399. The reversal of 199057391 is 193750991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 199057391 - 2¹⁰ = 199056367 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 (199057399) 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, 7656041 + ... + 7656066.

It is an arithmetic number, because the mean of its divisors is an integer number (53592378).

Almost surely, 2^199057391 is an apocalyptic number.

199057391 is a deficient number, since it is larger than the sum of its proper divisors (15312121).

199057391 is a wasteful number, since it uses less digits than its factorization.

199057391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15312120.

The product of its (nonzero) digits is 76545, while the sum is 44.

The square root of 199057391 is about 14108.7700030867. The cubic root of 199057391 is about 583.8833653594.

The spelling of 199057391 in words is "one hundred ninety-nine million, fifty-seven thousand, three hundred ninety-one".