1212211220 has 24 divisors (see below), whose sum is σ = 2777066208. Its totient is φ = 440804000.

The previous prime is 1212211213. The next prime is 1212211241. The reversal of 1212211220 is 221122121.

It is a junction number, because it is equal to n+sod(n) for n = 1212211195 and 1212211204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2754806 + ... + 2755245.

It is an arithmetic number, because the mean of its divisors is an integer number (115711092).

Almost surely, 2^1212211220 is an apocalyptic number.

1212211220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1212211220 is an abundant number, since it is smaller than the sum of its proper divisors (1564854988).

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

1212211220 is a wasteful number, since it uses less digits than its factorization.

1212211220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5510071 (or 5510069 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 1212211220 is about 34816.8238068897. The cubic root of 1212211220 is about 1066.2509549763.

Adding to 1212211220 its reverse (221122121), we get a palindrome (1433333341).

The spelling of 1212211220 in words is "one billion, two hundred twelve million, two hundred eleven thousand, two hundred twenty".