81386535 has 32 divisors (see below), whose sum is σ = 138475008. Its totient is φ = 40726400.

The previous prime is 81386533. The next prime is 81386549. The reversal of 81386535 is 53568318.

It is not a de Polignac number, because 81386535 - 2¹ = 81386533 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81386493 and 81386502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81386533) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16060 + ... + 20510.

It is an arithmetic number, because the mean of its divisors is an integer number (4327344).

Almost surely, 2^81386535 is an apocalyptic number.

81386535 is a deficient number, since it is larger than the sum of its proper divisors (57088473).

81386535 is a wasteful number, since it uses less digits than its factorization.

81386535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4535.

The product of its digits is 86400, while the sum is 39.

The square root of 81386535 is about 9021.4486087324. The cubic root of 81386535 is about 433.3620260422.

The spelling of 81386535 in words is "eighty-one million, three hundred eighty-six thousand, five hundred thirty-five".