819209881 has 16 divisors (see below), whose sum is σ = 961734400. Its totient is φ = 697485600.

The previous prime is 819209879. The next prime is 819209891. The reversal of 819209881 is 188902918.

It is not a de Polignac number, because 819209881 - 2¹ = 819209879 is a prime.

It is a super-2 number, since 2×819209881² = 1342209658256068322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (819209891) 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, 43885 + ... + 59701.

It is an arithmetic number, because the mean of its divisors is an integer number (60108400).

Almost surely, 2^819209881 is an apocalyptic number.

It is an amenable number.

819209881 is a deficient number, since it is larger than the sum of its proper divisors (142524519).

819209881 is a wasteful number, since it uses less digits than its factorization.

819209881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15989 (or 15975 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 46.

The square root of 819209881 is about 28621.8427254431. The cubic root of 819209881 is about 935.6894382207.

The spelling of 819209881 in words is "eight hundred nineteen million, two hundred nine thousand, eight hundred eighty-one".