81722154346560 has 1568 divisors, whose sum is σ = 378000698261760. Its totient is φ = 16334897135616.

The previous prime is 81722154346531. The next prime is 81722154346571. The reversal of 81722154346560 is 6564345122718.

81722154346560 is a `hidden beast` number, since 8 + 1 + 7 + 2 + 2 + 1 + 543 + 46 + 56 + 0 = 666.

It is a super-2 number, since 2×81722154346560² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 81722154346497 and 81722154346506.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 403239814 + ... + 403442426.

Almost surely, 2^{81722154346560} is an apocalyptic number.

81722154346560 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81722154346560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189000349130880).

81722154346560 is an abundant number, since it is smaller than the sum of its proper divisors (296278543915200).

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

81722154346560 is a wasteful number, since it uses less digits than its factorization.

81722154346560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202687 (or 202662 counting only the distinct ones).

The product of its (nonzero) digits is 9676800, while the sum is 54.

The spelling of 81722154346560 in words is "eighty-one trillion, seven hundred twenty-two billion, one hundred fifty-four million, three hundred forty-six thousand, five hundred sixty".