1221101112121 has 32 divisors (see below), whose sum is σ = 1371381840000. Its totient is φ = 1077881280000.

The previous prime is 1221101112113. The next prime is 1221101112151. The reversal of 1221101112121 is 1212111011221.

It is a cyclic number.

It is not a de Polignac number, because 1221101112121 - 2³ = 1221101112113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221101112095 and 1221101112104.

It is not an unprimeable number, because it can be changed into a prime (1221101112151) 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, 27574005 + ... + 27618253.

It is an arithmetic number, because the mean of its divisors is an integer number (42855682500).

Almost surely, 2^{1221101112121} is an apocalyptic number.

1221101112121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221101112121 is a deficient number, since it is larger than the sum of its proper divisors (150280727879).

1221101112121 is a wasteful number, since it uses less digits than its factorization.

1221101112121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44841.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 1221101112121 its reverse (1212111011221), we get a palindrome (2433212123342).

The spelling of 1221101112121 in words is "one trillion, two hundred twenty-one billion, one hundred one million, one hundred twelve thousand, one hundred twenty-one".