81422666 has 8 divisors (see below), whose sum is σ = 131528964. Its totient is φ = 37579680.

The previous prime is 81422651. The next prime is 81422683. The reversal of 81422666 is 66622418.

It can be written as a sum of positive squares in 2 ways, for example, as 59059225 + 22363441 = 7685^2 + 4729^2 .

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

It is a super-3 number, since 3×81422666³ (a number of 25 digits) contains 333 as substring.

It is an unprimeable number.

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, 1565795 + ... + 1565846.

Almost surely, 2^81422666 is an apocalyptic number.

81422666 is a deficient number, since it is larger than the sum of its proper divisors (50106298).

81422666 is a wasteful number, since it uses less digits than its factorization.

81422666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3131656.

The product of its digits is 27648, while the sum is 35.

The square root of 81422666 is about 9023.4508919814. The cubic root of 81422666 is about 433.4261459317.

The spelling of 81422666 in words is "eighty-one million, four hundred twenty-two thousand, six hundred sixty-six".