81822565 has 16 divisors (see below), whose sum is σ = 107904960. Its totient is φ = 59067520.

The previous prime is 81822563. The next prime is 81822583. The reversal of 81822565 is 56522818.

It is not a de Polignac number, because 81822565 - 2¹ = 81822563 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81822563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2106 + ... + 12964.

It is an arithmetic number, because the mean of its divisors is an integer number (6744060).

Almost surely, 2^81822565 is an apocalyptic number.

It is an amenable number.

81822565 is a deficient number, since it is larger than the sum of its proper divisors (26082395).

81822565 is a wasteful number, since it uses less digits than its factorization.

81822565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11012.

The product of its digits is 38400, while the sum is 37.

The square root of 81822565 is about 9045.5826235793. The cubic root of 81822565 is about 434.1345633125.

The spelling of 81822565 in words is "eighty-one million, eight hundred twenty-two thousand, five hundred sixty-five".