199026391 has 4 divisors (see below), whose sum is σ = 205889400. Its totient is φ = 192163384.

The previous prime is 199026389. The next prime is 199026407. The reversal of 199026391 is 193620991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 193620991 = 337 ⋅574543.

It is a cyclic number.

It is not a de Polignac number, because 199026391 - 2¹ = 199026389 is a prime.

It is a super-2 number, since 2×199026391² = 79223008628969762, which contains 22 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 (199024391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3431461 + ... + 3431518.

It is an arithmetic number, because the mean of its divisors is an integer number (51472350).

Almost surely, 2^199026391 is an apocalyptic number.

199026391 is a deficient number, since it is larger than the sum of its proper divisors (6863009).

199026391 is an equidigital number, since it uses as much as digits as its factorization.

199026391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6863008.

The product of its (nonzero) digits is 26244, while the sum is 40.

The square root of 199026391 is about 14107.6713528491. The cubic root of 199026391 is about 583.8530536254.

The spelling of 199026391 in words is "one hundred ninety-nine million, twenty-six thousand, three hundred ninety-one".