81183199894 has 8 divisors (see below), whose sum is σ = 125973930960. Its totient is φ = 39191889576.

The previous prime is 81183199879. The next prime is 81183199907. The reversal of 81183199894 is 49899138118.

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

It is a super-2 number, since 2×81183199894² (a number of 23 digits) 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 (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 699855114 + ... + 699855229.

It is an arithmetic number, because the mean of its divisors is an integer number (15746741370).

Almost surely, 2^81183199894 is an apocalyptic number.

81183199894 is a deficient number, since it is larger than the sum of its proper divisors (44790731066).

81183199894 is a wasteful number, since it uses less digits than its factorization.

81183199894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1399710374.

The product of its digits is 4478976, while the sum is 61.

The spelling of 81183199894 in words is "eighty-one billion, one hundred eighty-three million, one hundred ninety-nine thousand, eight hundred ninety-four".