81224623481 has 4 divisors (see below), whose sum is σ = 81394195200. Its totient is φ = 81055051764.

The previous prime is 81224623453. The next prime is 81224623483. The reversal of 81224623481 is 18432642218.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81224623481 is a prime.

It is a super-2 number, since 2×81224623481² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81224623483) 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, 84785141 + ... + 84786098.

It is an arithmetic number, because the mean of its divisors is an integer number (20348548800).

Almost surely, 2^81224623481 is an apocalyptic number.

It is an amenable number.

81224623481 is a deficient number, since it is larger than the sum of its proper divisors (169571719).

81224623481 is a wasteful number, since it uses less digits than its factorization.

81224623481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169571718.

The product of its digits is 147456, while the sum is 41.

The spelling of 81224623481 in words is "eighty-one billion, two hundred twenty-four million, six hundred twenty-three thousand, four hundred eighty-one".