81684835 has 8 divisors (see below), whose sum is σ = 98098560. Its totient is φ = 65296704.

The previous prime is 81684817. The next prime is 81684839. The reversal of 81684835 is 53848618.

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

It is a cyclic number.

It is not a de Polignac number, because 81684835 - 2²³ = 73296227 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81684791 and 81684800.

It is not an unprimeable number, because it can be changed into a prime (81684839) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1519 + ... + 12871.

It is an arithmetic number, because the mean of its divisors is an integer number (12262320).

Almost surely, 2^81684835 is an apocalyptic number.

81684835 is a deficient number, since it is larger than the sum of its proper divisors (16413725).

81684835 is a wasteful number, since it uses less digits than its factorization.

81684835 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12797.

The product of its digits is 184320, while the sum is 43.

The square root of 81684835 is about 9037.9663088551. The cubic root of 81684835 is about 433.8908370071.

The spelling of 81684835 in words is "eighty-one million, six hundred eighty-four thousand, eight hundred thirty-five".