1212221920 has 96 divisors (see below), whose sum is σ = 3524810688. Its totient is φ = 383643648.

The previous prime is 1212221909. The next prime is 1212221929. The reversal of 1212221920 is 291222121.

It is a junction number, because it is equal to n+sod(n) for n = 1212221891 and 1212221900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212221929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27069 + ... + 56188.

It is an arithmetic number, because the mean of its divisors is an integer number (36716778).

Almost surely, 2^1212221920 is an apocalyptic number.

1212221920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1212221920 is an abundant number, since it is smaller than the sum of its proper divisors (2312588768).

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

1212221920 is a wasteful number, since it uses less digits than its factorization.

1212221920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83292 (or 83284 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 1212221920 is about 34816.9774678963. The cubic root of 1212221920 is about 1066.2540921776.

The spelling of 1212221920 in words is "one billion, two hundred twelve million, two hundred twenty-one thousand, nine hundred twenty".