81524525760 has 448 divisors, whose sum is σ = 291709693440. Its totient is φ = 21432176640.

The previous prime is 81524525749. The next prime is 81524525779. The reversal of 81524525760 is 6752542518.

81524525760 is a `hidden beast` number, since 8 + 1 + 5 + 24 + 52 + 576 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 359138767 + ... + 359138993.

Almost surely, 2^81524525760 is an apocalyptic number.

81524525760 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 81524525760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145854846720).

81524525760 is an abundant number, since it is smaller than the sum of its proper divisors (210185167680).

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

81524525760 is a wasteful number, since it uses less digits than its factorization.

81524525760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661 (or 645 counting only the distinct ones).

The product of its (nonzero) digits is 672000, while the sum is 45.

The spelling of 81524525760 in words is "eighty-one billion, five hundred twenty-four million, five hundred twenty-five thousand, seven hundred sixty".