81501662626560 has 720 divisors, whose sum is σ = 318221937411840. Its totient is φ = 19752858132480.

The previous prime is 81501662626543. The next prime is 81501662626567. The reversal of 81501662626560 is 6562626610518.

81501662626560 is a `hidden beast` number, since 8 + 1 + 5 + 0 + 1 + 6 + 6 + 2 + 626 + 5 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

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 = 81501662626497 and 81501662626506.

It is not an unprimeable number, because it can be changed into a prime (81501662626567) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 6248683399 + ... + 6248696441.

It is an arithmetic number, because the mean of its divisors is an integer number (441974913072).

Almost surely, 2^{81501662626560} is an apocalyptic number.

81501662626560 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 81501662626560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159110968705920).

81501662626560 is an abundant number, since it is smaller than the sum of its proper divisors (236720274785280).

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

81501662626560 is a wasteful number, since it uses less digits than its factorization.

81501662626560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18566 (or 18543 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 54.

The spelling of 81501662626560 in words is "eighty-one trillion, five hundred one billion, six hundred sixty-two million, six hundred twenty-six thousand, five hundred sixty".