199778231 has 2 divisors, whose sum is σ = 199778232. Its totient is φ = 199778230.

The previous prime is 199778213. The next prime is 199778251. The reversal of 199778231 is 132877991.

Together with previous prime (199778213) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199778231 - 2¹⁴ = 199761847 is a prime.

It is a super-2 number, since 2×199778231² = 79822683162978722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199778251) 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 as a sum of consecutive naturals, namely, 99889115 + 99889116.

It is an arithmetic number, because the mean of its divisors is an integer number (99889116).

Almost surely, 2^199778231 is an apocalyptic number.

199778231 is a deficient number, since it is larger than the sum of its proper divisors (1).

199778231 is an equidigital number, since it uses as much as digits as its factorization.

199778231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 190512, while the sum is 47.

The square root of 199778231 is about 14134.2927308019. The cubic root of 199778231 is about 584.5873155370.

The spelling of 199778231 in words is "one hundred ninety-nine million, seven hundred seventy-eight thousand, two hundred thirty-one".