81422273 has 4 divisors (see below), whose sum is σ = 82337220. Its totient is φ = 80507328.

The previous prime is 81422207. The next prime is 81422291. The reversal of 81422273 is 37222418.

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 16265089 + 65157184 = 4033^2 + 8072^2 .

It is a cyclic number.

It is not a de Polignac number, because 81422273 - 2¹² = 81418177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81422293) 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, 457340 + ... + 457517.

It is an arithmetic number, because the mean of its divisors is an integer number (20584305).

Almost surely, 2^81422273 is an apocalyptic number.

It is an amenable number.

81422273 is a deficient number, since it is larger than the sum of its proper divisors (914947).

81422273 is an equidigital number, since it uses as much as digits as its factorization.

81422273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 914946.

The product of its digits is 5376, while the sum is 29.

The square root of 81422273 is about 9023.4291153641. The cubic root of 81422273 is about 433.4254485962.

The spelling of 81422273 in words is "eighty-one million, four hundred twenty-two thousand, two hundred seventy-three".