1220123111 has 2 divisors, whose sum is σ = 1220123112. Its totient is φ = 1220123110.

The previous prime is 1220123083. The next prime is 1220123117. The reversal of 1220123111 is 1113210221.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1220123111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220123117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610061555 + 610061556.

It is an arithmetic number, because the mean of its divisors is an integer number (610061556).

Almost surely, 2^1220123111 is an apocalyptic number.

1220123111 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220123111 is an equidigital number, since it uses as much as digits as its factorization.

1220123111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 14.

The square root of 1220123111 is about 34930.2606775272. The cubic root of 1220123111 is about 1068.5656709519.

Adding to 1220123111 its reverse (1113210221), we get a palindrome (2333333332).

The spelling of 1220123111 in words is "one billion, two hundred twenty million, one hundred twenty-three thousand, one hundred eleven".