81295159 has 4 divisors (see below), whose sum is σ = 88685640. Its totient is φ = 73904680.

The previous prime is 81295157. The next prime is 81295171. The reversal of 81295159 is 95159218.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81295159 - 2¹ = 81295157 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81295153) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3695224 + ... + 3695245.

It is an arithmetic number, because the mean of its divisors is an integer number (22171410).

Almost surely, 2^81295159 is an apocalyptic number.

81295159 is a deficient number, since it is larger than the sum of its proper divisors (7390481).

81295159 is a wasteful number, since it uses less digits than its factorization.

81295159 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7390480.

The product of its digits is 32400, while the sum is 40.

The square root of 81295159 is about 9016.3828113052. The cubic root of 81295159 is about 433.1997808686.

The spelling of 81295159 in words is "eighty-one million, two hundred ninety-five thousand, one hundred fifty-nine".