1221012431121 has 16 divisors (see below), whose sum is σ = 1860639678464. Its totient is φ = 697702899024.

The previous prime is 1221012431077. The next prime is 1221012431129. The reversal of 1221012431121 is 1211342101221.

It is not a de Polignac number, because 1221012431121 - 2¹⁴ = 1221012414737 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (1221012431129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61776 + ... + 1563918.

It is an arithmetic number, because the mean of its divisors is an integer number (116289979904).

Almost surely, 2^{1221012431121} is an apocalyptic number.

It is an amenable number.

1221012431121 is a deficient number, since it is larger than the sum of its proper divisors (639627247343).

1221012431121 is a wasteful number, since it uses less digits than its factorization.

1221012431121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1540860.

The product of its (nonzero) digits is 192, while the sum is 21.

Adding to 1221012431121 its reverse (1211342101221), we get a palindrome (2432354532342).

The spelling of 1221012431121 in words is "one trillion, two hundred twenty-one billion, twelve million, four hundred thirty-one thousand, one hundred twenty-one".