1212123221 has 8 divisors (see below), whose sum is σ = 1307040000. Its totient is φ = 1120318560.

The previous prime is 1212123203. The next prime is 1212123223. The reversal of 1212123221 is 1223212121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1212123221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1212123221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212123223) 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, 777221 + ... + 778778.

It is an arithmetic number, because the mean of its divisors is an integer number (163380000).

Almost surely, 2^1212123221 is an apocalyptic number.

It is an amenable number.

1212123221 is a deficient number, since it is larger than the sum of its proper divisors (94916779).

1212123221 is a wasteful number, since it uses less digits than its factorization.

1212123221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1556059.

The product of its digits is 96, while the sum is 17.

The square root of 1212123221 is about 34815.5600414527. The cubic root of 1212123221 is about 1066.2251532880.

Adding to 1212123221 its reverse (1223212121), we get a palindrome (2435335342).

Subtracting 1212123221 from its reverse (1223212121), we obtain a square (11088900 = 3330²).

The spelling of 1212123221 in words is "one billion, two hundred twelve million, one hundred twenty-three thousand, two hundred twenty-one".