81522841 has 3 divisors (see below), whose sum is σ = 81531871. Its totient is φ = 81513812.

The previous prime is 81522781. The next prime is 81522869. The reversal of 81522841 is 14822518.

The square root of 81522841 is 9029.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 81378441 + 144400 = 9021^2 + 380^2 .

It is not a de Polignac number, because 81522841 - 2¹⁷ = 81391769 is a prime.

It is a super-2 number, since 2×81522841² = 13291947209422562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81522641) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 4515 + ... + 13543.

Almost surely, 2^81522841 is an apocalyptic number.

81522841 is the 9029-th square number.

81522841 is the 4515-th centered octagonal number.

It is an amenable number.

81522841 is a deficient number, since it is larger than the sum of its proper divisors (9030).

81522841 is an frugal number, since it uses more digits than its factorization.

81522841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18058 (or 9029 counting only the distinct ones).

The product of its digits is 5120, while the sum is 31.

The cubic root of 81522841 is about 433.6038223799.

The spelling of 81522841 in words is "eighty-one million, five hundred twenty-two thousand, eight hundred forty-one".