81566662 has 8 divisors (see below), whose sum is σ = 123472800. Its totient is φ = 40409064.

The previous prime is 81566659. The next prime is 81566711. The reversal of 81566662 is 26666518.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 186862 + ... + 187297.

It is an arithmetic number, because the mean of its divisors is an integer number (15434100).

Almost surely, 2^81566662 is an apocalyptic number.

81566662 is a deficient number, since it is larger than the sum of its proper divisors (41906138).

81566662 is a wasteful number, since it uses less digits than its factorization.

81566662 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 374270.

The product of its digits is 103680, while the sum is 40.

The square root of 81566662 is about 9031.4263546795. The cubic root of 81566662 is about 433.6815001994.

It can be divided in two parts, 81566 and 662, that added together give a palindrome (82228).

The spelling of 81566662 in words is "eighty-one million, five hundred sixty-six thousand, six hundred sixty-two".