1221105539 has 2 divisors, whose sum is σ = 1221105540. Its totient is φ = 1221105538.

The previous prime is 1221105493. The next prime is 1221105541. The reversal of 1221105539 is 9355011221.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221105539 is a prime.

Together with 1221105541, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1221105569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610552769 + 610552770.

It is an arithmetic number, because the mean of its divisors is an integer number (610552770).

Almost surely, 2^1221105539 is an apocalyptic number.

1221105539 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221105539 is an equidigital number, since it uses as much as digits as its factorization.

1221105539 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2700, while the sum is 29.

The square root of 1221105539 is about 34944.3205542761. The cubic root of 1221105539 is about 1068.8523926202.

The spelling of 1221105539 in words is "one billion, two hundred twenty-one million, one hundred five thousand, five hundred thirty-nine".