1221212120001 has 16 divisors (see below), whose sum is σ = 1675724406144. Its totient is φ = 790510990464.

The previous prime is 1221212119999. The next prime is 1221212120027. The reversal of 1221212120001 is 1000212121221.

It is not a de Polignac number, because 1221212120001 - 2¹ = 1221212119999 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221212120041) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 11241540 + ... + 11349653.

It is an arithmetic number, because the mean of its divisors is an integer number (104732775384).

Almost surely, 2^{1221212120001} is an apocalyptic number.

It is an amenable number.

1221212120001 is a deficient number, since it is larger than the sum of its proper divisors (454512286143).

1221212120001 is a wasteful number, since it uses less digits than its factorization.

1221212120001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22591720.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1221212120001 its reverse (1000212121221), we get a palindrome (2221424241222).

The spelling of 1221212120001 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, one hundred twenty thousand, one".