827199891 has 16 divisors (see below), whose sum is σ = 1400550400. Its totient is φ = 472685544.

The previous prime is 827199881. The next prime is 827199911. The reversal of 827199891 is 198991728.

It is not a de Polignac number, because 827199891 - 2¹⁵ = 827167123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (827199851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2188171 + ... + 2188548.

It is an arithmetic number, because the mean of its divisors is an integer number (87534400).

Almost surely, 2^827199891 is an apocalyptic number.

827199891 is a deficient number, since it is larger than the sum of its proper divisors (573350509).

827199891 is a wasteful number, since it uses less digits than its factorization.

827199891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4376735 (or 4376729 counting only the distinct ones).

The product of its digits is 653184, while the sum is 54.

The square root of 827199891 is about 28761.0829246744. The cubic root of 827199891 is about 938.7216253688.

The spelling of 827199891 in words is "eight hundred twenty-seven million, one hundred ninety-nine thousand, eight hundred ninety-one".