81116582 has 4 divisors (see below), whose sum is σ = 121674876. Its totient is φ = 40558290.

The previous prime is 81116557. The next prime is 81116587. The reversal of 81116582 is 28561118.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 28561118 = 2 ⋅14280559.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81116587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20279144 + ... + 20279147.

It is an arithmetic number, because the mean of its divisors is an integer number (30418719).

Almost surely, 2^81116582 is an apocalyptic number.

81116582 is a deficient number, since it is larger than the sum of its proper divisors (40558294).

81116582 is a wasteful number, since it uses less digits than its factorization.

81116582 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40558293.

The product of its digits is 3840, while the sum is 32.

The square root of 81116582 is about 9006.4744489728. The cubic root of 81116582 is about 432.8823522485.

The spelling of 81116582 in words is "eighty-one million, one hundred sixteen thousand, five hundred eighty-two".