1221100012121 has 8 divisors (see below), whose sum is σ = 1332348629664. Its totient is φ = 1109891315520.

The previous prime is 1221100012103. The next prime is 1221100012127. The reversal of 1221100012121 is 1212100011221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221100012121 - 2¹⁸ = 1221099749977 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221100012096 and 1221100012105.

It is not an unprimeable number, because it can be changed into a prime (1221100012127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9916256 + ... + 10038641.

It is an arithmetic number, because the mean of its divisors is an integer number (166543578708).

Almost surely, 2^{1221100012121} is an apocalyptic number.

1221100012121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221100012121 is a deficient number, since it is larger than the sum of its proper divisors (111248617543).

1221100012121 is a wasteful number, since it uses less digits than its factorization.

1221100012121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19960471.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1221100012121 its reverse (1212100011221), we get a palindrome (2433200023342).

The spelling of 1221100012121 in words is "one trillion, two hundred twenty-one billion, one hundred million, twelve thousand, one hundred twenty-one".