81373320 has 192 divisors, whose sum is σ = 308880000. Its totient is φ = 18571392.

The previous prime is 81373301. The next prime is 81373351. The reversal of 81373320 is 2337318.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 123151 + ... + 123809.

It is an arithmetic number, because the mean of its divisors is an integer number (1608750).

Almost surely, 2^81373320 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 81373320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154440000).

81373320 is an abundant number, since it is smaller than the sum of its proper divisors (227506680).

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

81373320 is a wasteful number, since it uses less digits than its factorization.

81373320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 697 (or 676 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 81373320 is about 9020.7161578225. The cubic root of 81373320 is about 433.3385692990.

The spelling of 81373320 in words is "eighty-one million, three hundred seventy-three thousand, three hundred twenty".