81856222 has 8 divisors (see below), whose sum is σ = 140324976. Its totient is φ = 35081232.

The previous prime is 81856169. The next prime is 81856223. The reversal of 81856222 is 22265818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×81856222² = 13400882160226568, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81856223) 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 3 ways as a sum of consecutive naturals, for example, 2923423 + ... + 2923450.

It is an arithmetic number, because the mean of its divisors is an integer number (17540622).

Almost surely, 2^81856222 is an apocalyptic number.

81856222 is a deficient number, since it is larger than the sum of its proper divisors (58468754).

81856222 is a wasteful number, since it uses less digits than its factorization.

81856222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5846882.

The product of its digits is 15360, while the sum is 34.

The square root of 81856222 is about 9047.4428431463. The cubic root of 81856222 is about 434.1940809773.

The spelling of 81856222 in words is "eighty-one million, eight hundred fifty-six thousand, two hundred twenty-two".