81235782576 has 540 divisors, whose sum is σ = 270207486120. Its totient is φ = 23581808640.

The previous prime is 81235782559. The next prime is 81235782577. The reversal of 81235782576 is 67528753218.

81235782576 is a `hidden beast` number, since 8 + 12 + 3 + 57 + 8 + 2 + 576 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (81235782577) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 337077816 + ... + 337078056.

Almost surely, 2^81235782576 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 81235782576, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135103743060).

81235782576 is an abundant number, since it is smaller than the sum of its proper divisors (188971703544).

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

81235782576 is a wasteful number, since it uses less digits than its factorization.

81235782576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318 (or 278 counting only the distinct ones).

The product of its digits is 5644800, while the sum is 54.

The spelling of 81235782576 in words is "eighty-one billion, two hundred thirty-five million, seven hundred eighty-two thousand, five hundred seventy-six".