81290333 has 4 divisors (see below), whose sum is σ = 81452448. Its totient is φ = 81128220.

The previous prime is 81290329. The next prime is 81290351. The reversal of 81290333 is 33309218.

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.

It is a cyclic number.

It is not a de Polignac number, because 81290333 - 2² = 81290329 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81290296 and 81290305.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81290323) 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, 80303 + ... + 81308.

It is an arithmetic number, because the mean of its divisors is an integer number (20363112).

Almost surely, 2^81290333 is an apocalyptic number.

It is an amenable number.

81290333 is a deficient number, since it is larger than the sum of its proper divisors (162115).

81290333 is a wasteful number, since it uses less digits than its factorization.

81290333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162114.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 81290333 is about 9016.1151833814. The cubic root of 81290333 is about 433.1912085521.

The spelling of 81290333 in words is "eighty-one million, two hundred ninety thousand, three hundred thirty-three".