1221003233100 has 216 divisors, whose sum is σ = 4374553948128. Its totient is φ = 279045043200.

The previous prime is 1221003233057. The next prime is 1221003233111. The reversal of 1221003233100 is 13323001221.

1221003233100 is a `hidden beast` number, since 1 + 22 + 10 + 0 + 323 + 310 + 0 = 666.

It is a super-2 number, since 2×1221003233100² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 67911312 + ... + 67929288.

Almost surely, 2^{1221003233100} is an apocalyptic number.

1221003233100 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 1221003233100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2187276974064).

1221003233100 is an abundant number, since it is smaller than the sum of its proper divisors (3153550715028).

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

1221003233100 is a wasteful number, since it uses less digits than its factorization.

1221003233100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28785 (or 28775 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 1221003233100 its reverse (13323001221), we get a palindrome (1234326234321).

The spelling of 1221003233100 in words is "one trillion, two hundred twenty-one billion, three million, two hundred thirty-three thousand, one hundred".