81850320 has 120 divisors (see below), whose sum is σ = 278553600. Its totient is φ = 21535488.

The previous prime is 81850313. The next prime is 81850331. The reversal of 81850320 is 2305818.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 56161 + ... + 57599.

It is an arithmetic number, because the mean of its divisors is an integer number (2321280).

Almost surely, 2^81850320 is an apocalyptic number.

81850320 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81850320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139276800).

81850320 is an abundant number, since it is smaller than the sum of its proper divisors (196703280).

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

81850320 is a wasteful number, since it uses less digits than its factorization.

81850320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1537 (or 1528 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 81850320 is about 9047.1166677566. The cubic root of 81850320 is about 434.1836453012.

The spelling of 81850320 in words is "eighty-one million, eight hundred fifty thousand, three hundred twenty".