81286089408 has 392 divisors, whose sum is σ = 260120709120. Its totient is φ = 25110259200.

The previous prime is 81286089403. The next prime is 81286089457. The reversal of 81286089408 is 80498068218.

81286089408 is a `hidden beast` number, since 8 + 1 + 28 + 608 + 9 + 4 + 0 + 8 = 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 (81286089403) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 41662833 + ... + 41664783.

Almost surely, 2^81286089408 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 81286089408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130060354560).

81286089408 is an abundant number, since it is smaller than the sum of its proper divisors (178834619712).

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

81286089408 is a wasteful number, since it uses less digits than its factorization.

81286089408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2047 (or 2022 counting only the distinct ones).

The product of its (nonzero) digits is 1769472, while the sum is 54.

The spelling of 81286089408 in words is "eighty-one billion, two hundred eighty-six million, eighty-nine thousand, four hundred eight".