81333291 has 8 divisors (see below), whose sum is σ = 116786320. Its totient is φ = 50051232.

The previous prime is 81333283. The next prime is 81333311. The reversal of 81333291 is 19233318.

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

It is not a de Polignac number, because 81333291 - 2³ = 81333283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81333271) 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, 1042696 + ... + 1042773.

It is an arithmetic number, because the mean of its divisors is an integer number (14598290).

Almost surely, 2^81333291 is an apocalyptic number.

81333291 is a deficient number, since it is larger than the sum of its proper divisors (35453029).

81333291 is a wasteful number, since it uses less digits than its factorization.

81333291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2085485.

The product of its digits is 3888, while the sum is 30.

The square root of 81333291 is about 9018.4971586179. The cubic root of 81333291 is about 433.2675019653.

The spelling of 81333291 in words is "eighty-one million, three hundred thirty-three thousand, two hundred ninety-one".