81294331 has 4 divisors (see below), whose sum is σ = 85573000. Its totient is φ = 77015664.

The previous prime is 81294319. The next prime is 81294371. The reversal of 81294331 is 13349218.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 81294331 - 2⁵ = 81294299 is a prime.

It is a super-2 number, since 2×81294331² = 13217536505475122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81294293 and 81294302.

It is not an unprimeable number, because it can be changed into a prime (81294371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2139306 + ... + 2139343.

It is an arithmetic number, because the mean of its divisors is an integer number (21393250).

Almost surely, 2^81294331 is an apocalyptic number.

81294331 is a deficient number, since it is larger than the sum of its proper divisors (4278669).

81294331 is a wasteful number, since it uses less digits than its factorization.

81294331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4278668.

The product of its digits is 5184, while the sum is 31.

The square root of 81294331 is about 9016.3368947705. The cubic root of 81294331 is about 433.1983101347.

The spelling of 81294331 in words is "eighty-one million, two hundred ninety-four thousand, three hundred thirty-one".