1221111110207 has 2 divisors, whose sum is σ = 1221111110208. Its totient is φ = 1221111110206.

The previous prime is 1221111110123. The next prime is 1221111110209. The reversal of 1221111110207 is 7020111111221.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221111110207 - 2²⁶ = 1221044001343 is a prime.

It is a super-2 number, since 2×1221111110207² (a number of 25 digits) contains 22 as substring.

Together with 1221111110209, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221111110209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610555555103 + 610555555104.

It is an arithmetic number, because the mean of its divisors is an integer number (610555555104).

Almost surely, 2^{1221111110207} is an apocalyptic number.

1221111110207 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221111110207 is an equidigital number, since it uses as much as digits as its factorization.

1221111110207 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56, while the sum is 20.

Adding to 1221111110207 its reverse (7020111111221), we get a palindrome (8241222221428).

The spelling of 1221111110207 in words is "one trillion, two hundred twenty-one billion, one hundred eleven million, one hundred ten thousand, two hundred seven".