1220111011221 has 16 divisors (see below), whose sum is σ = 1628880274944. Its totient is φ = 812374756544.

The previous prime is 1220111011199. The next prime is 1220111011241. The reversal of 1220111011221 is 1221101110221.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1220111011221 - 2⁶ = 1220111011157 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1220111011221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220111011241) 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, 30004315 + ... + 30044951.

It is an arithmetic number, because the mean of its divisors is an integer number (101805017184).

Almost surely, 2^{1220111011221} is an apocalyptic number.

It is an amenable number.

1220111011221 is a deficient number, since it is larger than the sum of its proper divisors (408769263723).

1220111011221 is a wasteful number, since it uses less digits than its factorization.

1220111011221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53100.

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

Adding to 1220111011221 its reverse (1221101110221), we get a palindrome (2441212121442).

The spelling of 1220111011221 in words is "one trillion, two hundred twenty billion, one hundred eleven million, eleven thousand, two hundred twenty-one".