212220918 has 128 divisors (see below), whose sum is σ = 611251200. Its totient is φ = 53001216.

The previous prime is 212220901. The next prime is 212220919. The reversal of 212220918 is 819022212.

212220918 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 212220891 and 212220900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212220919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 92230 + ... + 94502.

It is an arithmetic number, because the mean of its divisors is an integer number (4775400).

Almost surely, 2^212220918 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 212220918, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (305625600).

212220918 is an abundant number, since it is smaller than the sum of its proper divisors (399030282).

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

212220918 is a wasteful number, since it uses less digits than its factorization.

212220918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2323 (or 2317 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 212220918 is about 14567.8041584859. The cubic root of 212220918 is about 596.4802425544.

The spelling of 212220918 in words is "two hundred twelve million, two hundred twenty thousand, nine hundred eighteen".