81839265 has 8 divisors (see below), whose sum is σ = 130942848. Its totient is φ = 43647600.

The previous prime is 81839243. The next prime is 81839269. The reversal of 81839265 is 56293818.

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

It is not a de Polignac number, because 81839265 - 2¹⁰ = 81838241 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81839269) 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, 2727961 + ... + 2727990.

It is an arithmetic number, because the mean of its divisors is an integer number (16367856).

Almost surely, 2^81839265 is an apocalyptic number.

It is an amenable number.

81839265 is a deficient number, since it is larger than the sum of its proper divisors (49103583).

81839265 is a wasteful number, since it uses less digits than its factorization.

81839265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5455959.

The product of its digits is 103680, while the sum is 42.

The square root of 81839265 is about 9046.5056789901. The cubic root of 81839265 is about 434.1640969504.

The spelling of 81839265 in words is "eighty-one million, eight hundred thirty-nine thousand, two hundred sixty-five".