1221100111003 has 2 divisors, whose sum is σ = 1221100111004. Its totient is φ = 1221100111002.

The previous prime is 1221100111001. The next prime is 1221100111051. The reversal of 1221100111003 is 3001110011221.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221100111003 - 2¹ = 1221100111001 is a prime.

Together with 1221100111001, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1221100111001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610550055501 + 610550055502.

It is an arithmetic number, because the mean of its divisors is an integer number (610550055502).

Almost surely, 2^{1221100111003} is an apocalyptic number.

1221100111003 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221100111003 is an equidigital number, since it uses as much as digits as its factorization.

1221100111003 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 1221100111003 its reverse (3001110011221), we get a palindrome (4222210122224).

The spelling of 1221100111003 in words is "one trillion, two hundred twenty-one billion, one hundred million, one hundred eleven thousand, three".