1221110121201 has 16 divisors (see below), whose sum is σ = 1680863612928. Its totient is φ = 787721144400.

The previous prime is 1221110121113. The next prime is 1221110121229. The reversal of 1221110121201 is 1021210111221.

It is a happy number.

It is not a de Polignac number, because 1221110121201 - 2²⁵ = 1221076566769 is a prime.

It is a super-2 number, since 2×1221110121201² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221110121251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41316 + ... + 1563306.

It is an arithmetic number, because the mean of its divisors is an integer number (105053975808).

Almost surely, 2^{1221110121201} is an apocalyptic number.

It is an amenable number.

1221110121201 is a deficient number, since it is larger than the sum of its proper divisors (459753491727).

1221110121201 is a wasteful number, since it uses less digits than its factorization.

1221110121201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1530652.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1221110121201 its reverse (1021210111221), we get a palindrome (2242320232422).

The spelling of 1221110121201 in words is "one trillion, two hundred twenty-one billion, one hundred ten million, one hundred twenty-one thousand, two hundred one".