81297835 has 4 divisors (see below), whose sum is σ = 97557408. Its totient is φ = 65038264.

The previous prime is 81297833. The next prime is 81297857. The reversal of 81297835 is 53879218.

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 81297835 - 2¹ = 81297833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81297791 and 81297800.

It is not an unprimeable number, because it can be changed into a prime (81297833) 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, 8129779 + ... + 8129788.

It is an arithmetic number, because the mean of its divisors is an integer number (24389352).

Almost surely, 2^81297835 is an apocalyptic number.

81297835 is a deficient number, since it is larger than the sum of its proper divisors (16259573).

81297835 is a wasteful number, since it uses less digits than its factorization.

81297835 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16259572.

The product of its digits is 120960, while the sum is 43.

The square root of 81297835 is about 9016.5312066226. The cubic root of 81297835 is about 433.2045340417.

The spelling of 81297835 in words is "eighty-one million, two hundred ninety-seven thousand, eight hundred thirty-five".