81425623680 has 256 divisors, whose sum is σ = 288890438400. Its totient is φ = 21675257856.

The previous prime is 81425623633. The next prime is 81425623709. The reversal of 81425623680 is 8632652418.

81425623680 is a `hidden beast` number, since 8 + 1 + 4 + 2 + 562 + 3 + 6 + 80 = 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 polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10588797 + ... + 10596483.

It is an arithmetic number, because the mean of its divisors is an integer number (1128478275).

Almost surely, 2^81425623680 is an apocalyptic number.

81425623680 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 81425623680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144445219200).

81425623680 is an abundant number, since it is smaller than the sum of its proper divisors (207464814720).

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

81425623680 is a wasteful number, since it uses less digits than its factorization.

81425623680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8328 (or 8310 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 45.

The spelling of 81425623680 in words is "eighty-one billion, four hundred twenty-five million, six hundred twenty-three thousand, six hundred eighty".