199801831 has 2 divisors, whose sum is σ = 199801832. Its totient is φ = 199801830.

The previous prime is 199801807. The next prime is 199801871. The reversal of 199801831 is 138108991.

It is a happy number.

It is an a-pointer prime, because the next prime (199801871) can be obtained adding 199801831 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199801831 - 2⁷ = 199801703 is a prime.

It is a super-2 number, since 2×199801831² = 79841543341905122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199801801) 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, 99900915 + 99900916.

It is an arithmetic number, because the mean of its divisors is an integer number (99900916).

Almost surely, 2^199801831 is an apocalyptic number.

199801831 is a deficient number, since it is larger than the sum of its proper divisors (1).

199801831 is an equidigital number, since it uses as much as digits as its factorization.

199801831 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 40.

The square root of 199801831 is about 14135.1275551372. The cubic root of 199801831 is about 584.6103339232.

The spelling of 199801831 in words is "one hundred ninety-nine million, eight hundred one thousand, eight hundred thirty-one".