1213121120 has 96 divisors (see below), whose sum is σ = 3090739680. Its totient is φ = 448450560.

The previous prime is 1213121113. The next prime is 1213121137. The reversal of 1213121120 is 211213121.

It is a junction number, because it is equal to n+sod(n) for n = 1213121095 and 1213121104.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 119774 + ... + 129506.

It is an arithmetic number, because the mean of its divisors is an integer number (32195205).

Almost surely, 2^1213121120 is an apocalyptic number.

1213121120 is a gapful number since it is divisible by the number (10) 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 1213121120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1545369840).

1213121120 is an abundant number, since it is smaller than the sum of its proper divisors (1877618560).

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

1213121120 is a wasteful number, since it uses less digits than its factorization.

1213121120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9808 (or 9800 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 14.

The square root of 1213121120 is about 34829.8883144922. Note that the first 3 decimals coincide. The cubic root of 1213121120 is about 1066.5176684241.

Adding to 1213121120 its reverse (211213121), we get a palindrome (1424334241).

The spelling of 1213121120 in words is "one billion, two hundred thirteen million, one hundred twenty-one thousand, one hundred twenty".