1221331012121 has 32 divisors (see below), whose sum is σ = 1425665691648. Its totient is φ = 1033973821440.

The previous prime is 1221331012079. The next prime is 1221331012127. The reversal of 1221331012121 is 1212101331221.

It is a cyclic number.

It is not a de Polignac number, because 1221331012121 - 2²² = 1221326817817 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221331012093 and 1221331012102.

It is not an unprimeable number, because it can be changed into a prime (1221331012127) 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, 8789441 + ... + 8927313.

It is an arithmetic number, because the mean of its divisors is an integer number (44552052864).

Almost surely, 2^{1221331012121} is an apocalyptic number.

1221331012121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221331012121 is a deficient number, since it is larger than the sum of its proper divisors (204334679527).

1221331012121 is a wasteful number, since it uses less digits than its factorization.

1221331012121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138401.

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 1221331012121 its reverse (1212101331221), we get a palindrome (2433432343342).

The spelling of 1221331012121 in words is "one trillion, two hundred twenty-one billion, three hundred thirty-one million, twelve thousand, one hundred twenty-one".