1220221111 has 2 divisors, whose sum is σ = 1220221112. Its totient is φ = 1220221110.

The previous prime is 1220221099. The next prime is 1220221127. The reversal of 1220221111 is 1111220221.

It is a weak prime.

It is an emirp because it is prime and its reverse (1111220221) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1220221111 is a prime.

It is a super-4 number, since 4×1220221111⁴ (a number of 37 digits) contains 4444 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1220221091 and 1220221100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220221141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610110555 + 610110556.

It is an arithmetic number, because the mean of its divisors is an integer number (610110556).

Almost surely, 2^1220221111 is an apocalyptic number.

1220221111 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220221111 is an equidigital number, since it uses as much as digits as its factorization.

1220221111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 1220221111 is about 34931.6634445026. The cubic root of 1220221111 is about 1068.5942791667.

Adding to 1220221111 its reverse (1111220221), we get a palindrome (2331441332).

It can be divided in two parts, 1220221 and 111, that multiplied together give a palindrome (135444531).

The spelling of 1220221111 in words is "one billion, two hundred twenty million, two hundred twenty-one thousand, one hundred eleven".