81222331604544 has 784 divisors, whose sum is σ = 277537069877760. Its totient is φ = 23351768432640.

The previous prime is 81222331604507. The next prime is 81222331604611. The reversal of 81222331604544 is 44540613322218.

81222331604544 is a `hidden beast` number, since 8 + 1 + 2 + 2 + 2 + 3 + 31 + 604 + 5 + 4 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 81222331604544.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 1433197329 + ... + 1433253999.

It is an arithmetic number, because the mean of its divisors is an integer number (354001364640).

Almost surely, 2^{81222331604544} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81222331604544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138768534938880).

81222331604544 is an abundant number, since it is smaller than the sum of its proper divisors (196314738273216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81222331604544 is a wasteful number, since it uses less digits than its factorization.

81222331604544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56870 (or 56845 counting only the distinct ones).

The product of its (nonzero) digits is 1105920, while the sum is 45.

The spelling of 81222331604544 in words is "eighty-one trillion, two hundred twenty-two billion, three hundred thirty-one million, six hundred four thousand, five hundred forty-four".