81814441 has 4 divisors (see below), whose sum is σ = 81917892. Its totient is φ = 81710992.

The previous prime is 81814433. The next prime is 81814471. The reversal of 81814441 is 14441818.

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

It can be written as a sum of positive squares in 2 ways, for example, as 44555625 + 37258816 = 6675^2 + 6104^2 .

It is a cyclic number.

It is not a de Polignac number, because 81814441 - 2³ = 81814433 is a prime.

It is a super-2 number, since 2×81814441² = 13387205512284962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81814471) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50530 + ... + 52123.

It is an arithmetic number, because the mean of its divisors is an integer number (20479473).

Almost surely, 2^81814441 is an apocalyptic number.

It is an amenable number.

81814441 is a deficient number, since it is larger than the sum of its proper divisors (103451).

81814441 is a wasteful number, since it uses less digits than its factorization.

81814441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103450.

The product of its digits is 4096, while the sum is 31.

The square root of 81814441 is about 9045.1335534640. The cubic root of 81814441 is about 434.1201947174.

The spelling of 81814441 in words is "eighty-one million, eight hundred fourteen thousand, four hundred forty-one".