81320192 has 36 divisors (see below), whose sum is σ = 167575296. Its totient is φ = 39344640.

The previous prime is 81320189. The next prime is 81320219. The reversal of 81320192 is 29102318.

It is a super-2 number, since 2×81320192² = 13225947253833728, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2813 + ... + 13059.

Almost surely, 2^81320192 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 81320192, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83787648).

81320192 is an abundant number, since it is smaller than the sum of its proper divisors (86255104).

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

81320192 is a wasteful number, since it uses less digits than its factorization.

81320192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10294 (or 10280 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 81320192 is about 9017.7708997290. The cubic root of 81320192 is about 433.2442409872.

The spelling of 81320192 in words is "eighty-one million, three hundred twenty thousand, one hundred ninety-two".