1221200221111 has 16 divisors (see below), whose sum is σ = 1330024449600. Its totient is φ = 1114504604928.

The previous prime is 1221200221051. The next prime is 1221200221123. The reversal of 1221200221111 is 1111220021221.

It is not a de Polignac number, because 1221200221111 - 2³⁵ = 1186840482743 is a prime.

It is a super-4 number, since 4×1221200221111⁴ (a number of 49 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221200221711) 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, 16991710 + ... + 17063428.

It is an arithmetic number, because the mean of its divisors is an integer number (83126528100).

Almost surely, 2^{1221200221111} is an apocalyptic number.

1221200221111 is a deficient number, since it is larger than the sum of its proper divisors (108824228489).

1221200221111 is a wasteful number, since it uses less digits than its factorization.

1221200221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86538.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1221200221111 its reverse (1111220021221), we get a palindrome (2332420242332).

The spelling of 1221200221111 in words is "one trillion, two hundred twenty-one billion, two hundred million, two hundred twenty-one thousand, one hundred eleven".