1221000221133 has 24 divisors (see below), whose sum is σ = 2198857542336. Its totient is φ = 634285828800.

The previous prime is 1221000221107. The next prime is 1221000221141. The reversal of 1221000221133 is 3311220001221.

It is not a de Polignac number, because 1221000221133 - 2⁸ = 1221000220877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221000221333) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 880951848 + ... + 880953233.

It is an arithmetic number, because the mean of its divisors is an integer number (91619064264).

Almost surely, 2^{1221000221133} is an apocalyptic number.

It is an amenable number.

1221000221133 is a deficient number, since it is larger than the sum of its proper divisors (977857321203).

1221000221133 is a wasteful number, since it uses less digits than its factorization.

1221000221133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1761905105 (or 1761905102 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 1221000221133 its reverse (3311220001221), we get a palindrome (4532220222354).

The spelling of 1221000221133 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one thousand, one hundred thirty-three".