81411166 has 4 divisors (see below), whose sum is σ = 122116752. Its totient is φ = 40705582.

The previous prime is 81411157. The next prime is 81411167. The reversal of 81411166 is 66111418.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66111418 = 2 ⋅33055709.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81411167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20352790 + ... + 20352793.

It is an arithmetic number, because the mean of its divisors is an integer number (30529188).

Almost surely, 2^81411166 is an apocalyptic number.

81411166 is a deficient number, since it is larger than the sum of its proper divisors (40705586).

81411166 is a wasteful number, since it uses less digits than its factorization.

81411166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40705585.

The product of its digits is 1152, while the sum is 28.

The square root of 81411166 is about 9022.8136409880. The cubic root of 81411166 is about 433.4057395117.

The spelling of 81411166 in words is "eighty-one million, four hundred eleven thousand, one hundred sixty-six".