1221111221273 has 2 divisors, whose sum is σ = 1221111221274. Its totient is φ = 1221111221272.

The previous prime is 1221111221219. The next prime is 1221111221311. The reversal of 1221111221273 is 3721221111221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 940225001104 + 280886220169 = 969652^2 + 529987^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221111221273 - 2⁸ = 1221111221017 is a prime.

It is a super-2 number, since 2×1221111221273² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1221111221873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610555610636 + 610555610637.

It is an arithmetic number, because the mean of its divisors is an integer number (610555610637).

Almost surely, 2^{1221111221273} is an apocalyptic number.

It is an amenable number.

1221111221273 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221111221273 is an equidigital number, since it uses as much as digits as its factorization.

1221111221273 is an evil number, because the sum of its binary digits is even.

The product of its digits is 672, while the sum is 26.

Adding to 1221111221273 its reverse (3721221111221), we get a palindrome (4942332332494).

It can be divided in two parts, 1221111221 and 273, that multiplied together give a palindrome (333363363333).

The spelling of 1221111221273 in words is "one trillion, two hundred twenty-one billion, one hundred eleven million, two hundred twenty-one thousand, two hundred seventy-three".