81307308 has 54 divisors (see below), whose sum is σ = 201699876. Its totient is φ = 25488576.

The previous prime is 81307307. The next prime is 81307313. The reversal of 81307308 is 80370318.

It is a super-2 number, since 2×81307308² = 13221756668413728, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81307307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 593416 + ... + 593552.

Almost surely, 2^81307308 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 81307308, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100849938).

81307308 is an abundant number, since it is smaller than the sum of its proper divisors (120392568).

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

81307308 is a wasteful number, since it uses less digits than its factorization.

81307308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 81307308 is about 9017.0565042036. The cubic root of 81307308 is about 433.2213593654.

The spelling of 81307308 in words is "eighty-one million, three hundred seven thousand, three hundred eight".