81369792 has 252 divisors, whose sum is σ = 287533080. Its totient is φ = 22498560.

The previous prime is 81369781. The next prime is 81369809. The reversal of 81369792 is 29796318.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is a tau number, because it is divible by the number of its divisors (252).

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

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2624817 + ... + 2624847.

Almost surely, 2^81369792 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 81369792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143766540).

81369792 is an abundant number, since it is smaller than the sum of its proper divisors (206163288).

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

81369792 is a wasteful number, since it uses less digits than its factorization.

81369792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97 (or 43 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 81369792 is about 9020.5206058187. The cubic root of 81369792 is about 433.3323066379.

The spelling of 81369792 in words is "eighty-one million, three hundred sixty-nine thousand, seven hundred ninety-two".