81013219392 has 224 divisors, whose sum is σ = 250926803200. Its totient is φ = 23057879040.

The previous prime is 81013219349. The next prime is 81013219403. The reversal of 81013219392 is 29391231018.

It is a tau number, because it is divible by the number of its divisors (224).

It is a self number, because there is not a number n which added to its sum of digits gives 81013219392.

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, 18239892 + ... + 18244332.

Almost surely, 2^81013219392 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 81013219392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125463401600).

81013219392 is an abundant number, since it is smaller than the sum of its proper divisors (169913583808).

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

81013219392 is a wasteful number, since it uses less digits than its factorization.

81013219392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4754 (or 4730 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 39.

The spelling of 81013219392 in words is "eighty-one billion, thirteen million, two hundred nineteen thousand, three hundred ninety-two".