81311182 has 4 divisors (see below), whose sum is σ = 121966776. Its totient is φ = 40655590.

The previous prime is 81311179. The next prime is 81311189. The reversal of 81311182 is 28111318.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×81311182² = 13223016636474248, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81311189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20327794 + ... + 20327797.

It is an arithmetic number, because the mean of its divisors is an integer number (30491694).

Almost surely, 2^81311182 is an apocalyptic number.

81311182 is a deficient number, since it is larger than the sum of its proper divisors (40655594).

81311182 is a wasteful number, since it uses less digits than its factorization.

81311182 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40655593.

The product of its digits is 384, while the sum is 25.

The square root of 81311182 is about 9017.2713167565. The cubic root of 81311182 is about 433.2282397346.

The spelling of 81311182 in words is "eighty-one million, three hundred eleven thousand, one hundred eighty-two".