1221111122001 has 16 divisors (see below), whose sum is σ = 1684321757760. Its totient is φ = 785988302400.

The previous prime is 1221111121969. The next prime is 1221111122027. The reversal of 1221111122001 is 1002211111221.

It is a happy number.

It is not a de Polignac number, because 1221111122001 - 2⁵ = 1221111121969 is a prime.

It is a super-2 number, since 2×1221111122001² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221111122081) 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, 6934026 + ... + 7107948.

It is an arithmetic number, because the mean of its divisors is an integer number (105270109860).

Almost surely, 2^{1221111122001} is an apocalyptic number.

It is an amenable number.

1221111122001 is a deficient number, since it is larger than the sum of its proper divisors (463210635759).

1221111122001 is a wasteful number, since it uses less digits than its factorization.

1221111122001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254656.

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

Adding to 1221111122001 its reverse (1002211111221), we get a palindrome (2223322233222).

The spelling of 1221111122001 in words is "one trillion, two hundred twenty-one billion, one hundred eleven million, one hundred twenty-two thousand, one".