81839147 has 8 divisors (see below), whose sum is σ = 88226544. Its totient is φ = 75464928.

The previous prime is 81839123. The next prime is 81839159. The reversal of 81839147 is 74193818.

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 81839147 - 2²² = 77644843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81839047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12413 + ... + 17825.

It is an arithmetic number, because the mean of its divisors is an integer number (11028318).

Almost surely, 2^81839147 is an apocalyptic number.

81839147 is a deficient number, since it is larger than the sum of its proper divisors (6387397).

81839147 is a wasteful number, since it uses less digits than its factorization.

81839147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6589.

The product of its digits is 48384, while the sum is 41.

The square root of 81839147 is about 9046.4991571326. The cubic root of 81839147 is about 434.1638882837.

The spelling of 81839147 in words is "eighty-one million, eight hundred thirty-nine thousand, one hundred forty-seven".