81799326 has 48 divisors (see below), whose sum is σ = 206700000. Its totient is φ = 23369472.

The previous prime is 81799307. The next prime is 81799327. The reversal of 81799326 is 62399718.

It is a super-2 number, since 2×81799326² = 13382259468108552, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81799327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 451 + ... + 12798.

It is an arithmetic number, because the mean of its divisors is an integer number (4306250).

Almost surely, 2^81799326 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81799326, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103350000).

81799326 is an abundant number, since it is smaller than the sum of its proper divisors (124900674).

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

81799326 is a wasteful number, since it uses less digits than its factorization.

81799326 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13278 (or 13261 counting only the distinct ones).

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

The square root of 81799326 is about 9044.2979827071. The cubic root of 81799326 is about 434.0934588877.

The spelling of 81799326 in words is "eighty-one million, seven hundred ninety-nine thousand, three hundred twenty-six".