81817442 has 8 divisors (see below), whose sum is σ = 140258496. Its totient is φ = 35064612.

The previous prime is 81817399. The next prime is 81817453. The reversal of 81817442 is 24471818.

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

It is an unprimeable number.

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, 2922038 + ... + 2922065.

It is an arithmetic number, because the mean of its divisors is an integer number (17532312).

Almost surely, 2^81817442 is an apocalyptic number.

81817442 is a deficient number, since it is larger than the sum of its proper divisors (58441054).

81817442 is a wasteful number, since it uses less digits than its factorization.

81817442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5844112.

The product of its digits is 14336, while the sum is 35.

The square root of 81817442 is about 9045.2994422518. The cubic root of 81817442 is about 434.1255025773.

The spelling of 81817442 in words is "eighty-one million, eight hundred seventeen thousand, four hundred forty-two".