8121312 has 72 divisors (see below), whose sum is σ = 23370984. Its totient is φ = 2674944.

The previous prime is 8121307. The next prime is 8121319. The reversal of 8121312 is 2131218.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8121319) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 46858 + ... + 47030.

It is an arithmetic number, because the mean of its divisors is an integer number (324597).

Almost surely, 2^8121312 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 8121312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11685492).

8121312 is an abundant number, since it is smaller than the sum of its proper divisors (15249672).

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

8121312 is a wasteful number, since it uses less digits than its factorization.

8121312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352 (or 341 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

The square root of 8121312 is about 2849.7915713259. The cubic root of 8121312 is about 201.0058660202.

It can be divided in two parts, 81213 and 12, that added together give a square (81225 = 285²).

The spelling of 8121312 in words is "eight million, one hundred twenty-one thousand, three hundred twelve".