81168742 has 8 divisors (see below), whose sum is σ = 121791600. Its totient is φ = 40571544.

The previous prime is 81168739. The next prime is 81168743. The reversal of 81168742 is 24786118.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81168743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7759 + ... + 14917.

It is an arithmetic number, because the mean of its divisors is an integer number (15223950).

Almost surely, 2^81168742 is an apocalyptic number.

81168742 is a deficient number, since it is larger than the sum of its proper divisors (40622858).

81168742 is a wasteful number, since it uses less digits than its factorization.

81168742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12830.

The product of its digits is 21504, while the sum is 37.

The square root of 81168742 is about 9009.3696782849. The cubic root of 81168742 is about 432.9751171104.

The spelling of 81168742 in words is "eighty-one million, one hundred sixty-eight thousand, seven hundred forty-two".