8181320 has 64 divisors (see below), whose sum is σ = 21427200. Its totient is φ = 2753280.

The previous prime is 8181317. The next prime is 8181347. The reversal of 8181320 is 231818.

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16841 + ... + 17319.

It is an arithmetic number, because the mean of its divisors is an integer number (334800).

Almost surely, 2^8181320 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 8181320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10713600).

8181320 is an abundant number, since it is smaller than the sum of its proper divisors (13245880).

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

8181320 is a wasteful number, since it uses less digits than its factorization.

8181320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 558 (or 554 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 8181320 is about 2860.3006834947. The cubic root of 8181320 is about 201.4997260000.

The spelling of 8181320 in words is "eight million, one hundred eighty-one thousand, three hundred twenty".