1221023311100 has 18 divisors (see below), whose sum is σ = 2649620585304. Its totient is φ = 488409324400.

The previous prime is 1221023311097. The next prime is 1221023311201. The reversal of 1221023311100 is 11133201221.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6105116456 + ... + 6105116655.

It is an arithmetic number, because the mean of its divisors is an integer number (147201143628).

Almost surely, 2^{1221023311100} is an apocalyptic number.

1221023311100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221023311100 is an abundant number, since it is smaller than the sum of its proper divisors (1428597274204).

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

1221023311100 is a wasteful number, since it uses less digits than its factorization.

1221023311100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12210233125 (or 12210233118 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 1221023311100 its reverse (11133201221), we get a palindrome (1232156512321).

The spelling of 1221023311100 in words is "one trillion, two hundred twenty-one billion, twenty-three million, three hundred eleven thousand, one hundred".