1220111211989 has 2 divisors, whose sum is σ = 1220111211990. Its totient is φ = 1220111211988.

The previous prime is 1220111211953. The next prime is 1220111212051. The reversal of 1220111211989 is 9891121110221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 851989919089 + 368121292900 = 923033^2 + 606730^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220111211989 - 2²⁰ = 1220110163413 is a prime.

It is a super-2 number, since 2×1220111211989² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220111211589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610055605994 + 610055605995.

It is an arithmetic number, because the mean of its divisors is an integer number (610055605995).

Almost surely, 2^{1220111211989} is an apocalyptic number.

It is an amenable number.

1220111211989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220111211989 is an equidigital number, since it uses as much as digits as its factorization.

1220111211989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 38.

The spelling of 1220111211989 in words is "one trillion, two hundred twenty billion, one hundred eleven million, two hundred eleven thousand, nine hundred eighty-nine".