7218312 has 32 divisors (see below), whose sum is σ = 18319200. Its totient is φ = 2370192.

The previous prime is 7218311. The next prime is 7218317. The reversal of 7218312 is 2138127.

It is an ABA number since it can be written as A⋅B^A, here for A=3, B=134.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (7218311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107703 + ... + 107769.

It is an arithmetic number, because the mean of its divisors is an integer number (572475).

Almost surely, 2^7218312 is an apocalyptic number.

It is an amenable number.

7218312 is an abundant number, since it is smaller than the sum of its proper divisors (11100888).

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

7218312 is an frugal number, since it uses more digits than its factorization.

7218312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210 (or 72 counting only the distinct ones).

The product of its digits is 672, while the sum is 24.

The square root of 7218312 is about 2686.6916458723. The cubic root of 7218312 is about 193.2614424212.

7218312 divided by its sum of digits (24) gives a cube (300763 = 67³).

The spelling of 7218312 in words is "seven million, two hundred eighteen thousand, three hundred twelve".