81834691 has 4 divisors (see below), whose sum is σ = 86141800. Its totient is φ = 77527584.

The previous prime is 81834677. The next prime is 81834749. The reversal of 81834691 is 19643818.

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 81834691 - 2²⁵ = 48280259 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81834631) 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, 2153526 + ... + 2153563.

It is an arithmetic number, because the mean of its divisors is an integer number (21535450).

Almost surely, 2^81834691 is an apocalyptic number.

81834691 is a deficient number, since it is larger than the sum of its proper divisors (4307109).

81834691 is a wasteful number, since it uses less digits than its factorization.

81834691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4307108.

The product of its digits is 41472, while the sum is 40.

The square root of 81834691 is about 9046.2528706642. The cubic root of 81834691 is about 434.1560083164.

The spelling of 81834691 in words is "eighty-one million, eight hundred thirty-four thousand, six hundred ninety-one".