81912895 has 8 divisors (see below), whose sum is σ = 103469040. Its totient is φ = 62081280.

The previous prime is 81912877. The next prime is 81912937. The reversal of 81912895 is 59821918.

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

It is not a de Polignac number, because 81912895 - 2¹³ = 81904703 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 431026 + ... + 431215.

It is an arithmetic number, because the mean of its divisors is an integer number (12933630).

Almost surely, 2^81912895 is an apocalyptic number.

81912895 is a deficient number, since it is larger than the sum of its proper divisors (21556145).

81912895 is a wasteful number, since it uses less digits than its factorization.

81912895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 862265.

The product of its digits is 51840, while the sum is 43.

The square root of 81912895 is about 9050.5742911707. The cubic root of 81912895 is about 434.2942623435.

The spelling of 81912895 in words is "eighty-one million, nine hundred twelve thousand, eight hundred ninety-five".