81864196 has 24 divisors (see below), whose sum is σ = 146606936. Its totient is φ = 39985920.

The previous prime is 81864193. The next prime is 81864221. The reversal of 81864196 is 69146818.

It can be written as a sum of positive squares in 4 ways, for example, as 7214596 + 74649600 = 2686^2 + 8640^2 .

It is not an unprimeable number, because it can be changed into a prime (81864191) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37240 + ... + 39376.

Almost surely, 2^81864196 is an apocalyptic number.

It is an amenable number.

81864196 is a deficient number, since it is larger than the sum of its proper divisors (64742740).

81864196 is a wasteful number, since it uses less digits than its factorization.

81864196 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2359 (or 2357 counting only the distinct ones).

The product of its digits is 82944, while the sum is 43.

The square root of 81864196 is about 9047.8835094181. The cubic root of 81864196 is about 434.2081794828.

The spelling of 81864196 in words is "eighty-one million, eight hundred sixty-four thousand, one hundred ninety-six".