81578327040 has 2112 divisors, whose sum is σ = 386263987200. Its totient is φ = 16052649984.

The previous prime is 81578326969. The next prime is 81578327053. The reversal of 81578327040 is 4072387518.

81578327040 is a `hidden beast` number, since 8 + 1 + 578 + 3 + 2 + 70 + 4 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 2813045746 + ... + 2813045774.

Almost surely, 2^81578327040 is an apocalyptic number.

81578327040 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 81578327040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (193131993600).

81578327040 is an abundant number, since it is smaller than the sum of its proper divisors (304685660160).

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

81578327040 is a wasteful number, since it uses less digits than its factorization.

81578327040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112 (or 82 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 45.

The spelling of 81578327040 in words is "eighty-one billion, five hundred seventy-eight million, three hundred twenty-seven thousand, forty".