81422665 has 8 divisors (see below), whose sum is σ = 98675208. Its totient is φ = 64492800.

The previous prime is 81422651. The next prime is 81422683. The reversal of 81422665 is 56622418.

It can be written as a sum of positive squares in 4 ways, for example, as 41011216 + 40411449 = 6404^2 + 6357^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81422665 - 2⁹ = 81422153 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81422665.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80112 + ... + 81121.

It is an arithmetic number, because the mean of its divisors is an integer number (12334401).

Almost surely, 2^81422665 is an apocalyptic number.

It is an amenable number.

81422665 is a deficient number, since it is larger than the sum of its proper divisors (17252543).

81422665 is a wasteful number, since it uses less digits than its factorization.

81422665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161339.

The product of its digits is 23040, while the sum is 34.

The square root of 81422665 is about 9023.4508365702. The cubic root of 81422665 is about 433.4261441573.

The spelling of 81422665 in words is "eighty-one million, four hundred twenty-two thousand, six hundred sixty-five".