1221001103 has 4 divisors (see below), whose sum is σ = 1395429840. Its totient is φ = 1046572368.

The previous prime is 1221001097. The next prime is 1221001127. The reversal of 1221001103 is 3011001221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221001103 - 2¹⁶ = 1220935567 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221001153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87214358 + ... + 87214371.

It is an arithmetic number, because the mean of its divisors is an integer number (348857460).

Almost surely, 2^1221001103 is an apocalyptic number.

1221001103 is a deficient number, since it is larger than the sum of its proper divisors (174428737).

1221001103 is an equidigital number, since it uses as much as digits as its factorization.

1221001103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174428736.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 1221001103 is about 34942.8262022407. The cubic root of 1221001103 is about 1068.8219202744.

Adding to 1221001103 its reverse (3011001221), we get a palindrome (4232002324).

The spelling of 1221001103 in words is "one billion, two hundred twenty-one million, one thousand, one hundred three".