81306182 has 4 divisors (see below), whose sum is σ = 121959276. Its totient is φ = 40653090.

The previous prime is 81306139. The next prime is 81306191. The reversal of 81306182 is 28160318.

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

It is a super-2 number, since 2×81306182² = 13221390462834248, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20326544 + ... + 20326547.

It is an arithmetic number, because the mean of its divisors is an integer number (30489819).

Almost surely, 2^81306182 is an apocalyptic number.

81306182 is a deficient number, since it is larger than the sum of its proper divisors (40653094).

81306182 is a wasteful number, since it uses less digits than its factorization.

81306182 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40653093.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 81306182 is about 9016.9940667608. The cubic root of 81306182 is about 433.2193595062.

The spelling of 81306182 in words is "eighty-one million, three hundred six thousand, one hundred eighty-two".