81833261 has 4 divisors (see below), whose sum is σ = 81885792. Its totient is φ = 81780732.

The previous prime is 81833221. The next prime is 81833263. The reversal of 81833261 is 16233818.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16233818 = 2 ⋅8116909.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81833261 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81833263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23855 + ... + 27068.

It is an arithmetic number, because the mean of its divisors is an integer number (20471448).

Almost surely, 2^81833261 is an apocalyptic number.

It is an amenable number.

81833261 is a deficient number, since it is larger than the sum of its proper divisors (52531).

81833261 is a wasteful number, since it uses less digits than its factorization.

81833261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52530.

The product of its digits is 6912, while the sum is 32.

The square root of 81833261 is about 9046.1738320685. The cubic root of 81833261 is about 434.1534794512.

The spelling of 81833261 in words is "eighty-one million, eight hundred thirty-three thousand, two hundred sixty-one".