81493074432 has 480 divisors, whose sum is σ = 306146744640. Its totient is φ = 21165096960.

The previous prime is 81493074431. The next prime is 81493074449. The reversal of 81493074432 is 23447039418.

81493074432 is a `hidden beast` number, since 8 + 149 + 3 + 0 + 74 + 432 = 666.

It is a super-2 number, since 2×81493074432² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81493074431) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7445668 + ... + 7456604.

It is an arithmetic number, because the mean of its divisors is an integer number (637805718).

Almost surely, 2^81493074432 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 81493074432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153073372320).

81493074432 is an abundant number, since it is smaller than the sum of its proper divisors (224653670208).

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

81493074432 is a wasteful number, since it uses less digits than its factorization.

81493074432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10989 (or 10960 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

The spelling of 81493074432 in words is "eighty-one billion, four hundred ninety-three million, seventy-four thousand, four hundred thirty-two".