212123220 has 192 divisors, whose sum is σ = 661893120. Its totient is φ = 50554368.

The previous prime is 212123203. The next prime is 212123237. The reversal of 212123220 is 22321212.

It is a happy number.

212123220 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (212123203) and next prime (212123237).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 212123220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1982407 + ... + 1982513.

It is an arithmetic number, because the mean of its divisors is an integer number (3447360).

Almost surely, 2^212123220 is an apocalyptic number.

212123220 is a gapful number since it is divisible by the number (20) 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 212123220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (330946560).

212123220 is an abundant number, since it is smaller than the sum of its proper divisors (449769900).

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

212123220 is a wasteful number, since it uses less digits than its factorization.

212123220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222 (or 220 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 212123220 is about 14564.4505560629. The cubic root of 212123220 is about 596.3886966439.

Adding to 212123220 its reverse (22321212), we get a palindrome (234444432).

The spelling of 212123220 in words is "two hundred twelve million, one hundred twenty-three thousand, two hundred twenty".