1223121120 has 192 divisors, whose sum is σ = 4283725824. Its totient is φ = 291317760.

The previous prime is 1223121043. The next prime is 1223121127. The reversal of 1223121120 is 211213221.

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 1223121120.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1223121127) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 190279 + ... + 196601.

It is an arithmetic number, because the mean of its divisors is an integer number (22311072).

Almost surely, 2^1223121120 is an apocalyptic number.

1223121120 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 1223121120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2141862912).

1223121120 is an abundant number, since it is smaller than the sum of its proper divisors (3060604704).

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

1223121120 is a wasteful number, since it uses less digits than its factorization.

1223121120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6385 (or 6377 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1223121120 is about 34973.1485571431. The cubic root of 1223121120 is about 1069.4401589923.

Adding to 1223121120 its reverse (211213221), we get a palindrome (1434334341).

The spelling of 1223121120 in words is "one billion, two hundred twenty-three million, one hundred twenty-one thousand, one hundred twenty".