81287459 has 4 divisors (see below), whose sum is σ = 88677240. Its totient is φ = 73897680.

The previous prime is 81287447. The next prime is 81287467. The reversal of 81287459 is 95478218.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81287459 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81287429) 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, 3694874 + ... + 3694895.

It is an arithmetic number, because the mean of its divisors is an integer number (22169310).

Almost surely, 2^81287459 is an apocalyptic number.

81287459 is a deficient number, since it is larger than the sum of its proper divisors (7389781).

81287459 is a wasteful number, since it uses less digits than its factorization.

81287459 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7389780.

The product of its digits is 161280, while the sum is 44.

The square root of 81287459 is about 9015.9558006902. The cubic root of 81287459 is about 433.1861033685.

The spelling of 81287459 in words is "eighty-one million, two hundred eighty-seven thousand, four hundred fifty-nine".