1223312100 has 144 divisors (see below), whose sum is σ = 3636558912. Its totient is φ = 317399040.

The previous prime is 1223312089. The next prime is 1223312107. The reversal of 1223312100 is 12133221.

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 1223312100.

It is not an unprimeable number, because it can be changed into a prime (1223312107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1817364 + ... + 1818036.

Almost surely, 2^1223312100 is an apocalyptic number.

1223312100 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 1223312100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1818279456).

1223312100 is an abundant number, since it is smaller than the sum of its proper divisors (2413246812).

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

1223312100 is a wasteful number, since it uses less digits than its factorization.

1223312100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 846 (or 839 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 1223312100 is about 34975.8788309887. The cubic root of 1223312100 is about 1069.4958174356.

Adding to 1223312100 its reverse (12133221), we get a palindrome (1235445321).

The spelling of 1223312100 in words is "one billion, two hundred twenty-three million, three hundred twelve thousand, one hundred".