81319895 has 8 divisors (see below), whose sum is σ = 100221504. Its totient is φ = 63297504.

The previous prime is 81319859. The next prime is 81319919. The reversal of 81319895 is 59891318.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81319895 - 2¹² = 81315799 is a prime.

It is a super-2 number, since 2×81319895² = 13225850645622050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 219599 + ... + 219968.

It is an arithmetic number, because the mean of its divisors is an integer number (12527688).

Almost surely, 2^81319895 is an apocalyptic number.

81319895 is a deficient number, since it is larger than the sum of its proper divisors (18901609).

81319895 is a wasteful number, since it uses less digits than its factorization.

81319895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439609.

The product of its digits is 77760, while the sum is 44.

The square root of 81319895 is about 9017.7544322298. The cubic root of 81319895 is about 433.2437135507.

The spelling of 81319895 in words is "eighty-one million, three hundred nineteen thousand, eight hundred ninety-five".