81418281984 has 528 divisors, whose sum is σ = 272530702080. Its totient is φ = 23197777920.

The previous prime is 81418281943. The next prime is 81418281991. The reversal of 81418281984 is 48918281418.

It is a happy number.

It is a super-2 number, since 2×81418281984² (a number of 23 digits) contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 81418281984.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 106988164 + ... + 106988924.

Almost surely, 2^81418281984 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 81418281984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136265351040).

81418281984 is an abundant number, since it is smaller than the sum of its proper divisors (191112420096).

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

81418281984 is a wasteful number, since it uses less digits than its factorization.

81418281984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 866 (or 845 counting only the distinct ones).

The product of its digits is 1179648, while the sum is 54.

The spelling of 81418281984 in words is "eighty-one billion, four hundred eighteen million, two hundred eighty-one thousand, nine hundred eighty-four".