1221444131377 has 2 divisors, whose sum is σ = 1221444131378. Its totient is φ = 1221444131376.

The previous prime is 1221444131333. The next prime is 1221444131399. The reversal of 1221444131377 is 7731314441221.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 708965684001 + 512478447376 = 842001^2 + 715876^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221444131377 - 2¹⁹ = 1221443607089 is a prime.

It is a super-2 number, since 2×1221444131377² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221444131977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610722065688 + 610722065689.

It is an arithmetic number, because the mean of its divisors is an integer number (610722065689).

Almost surely, 2^{1221444131377} is an apocalyptic number.

It is an amenable number.

1221444131377 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221444131377 is an equidigital number, since it uses as much as digits as its factorization.

1221444131377 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112896, while the sum is 40.

Adding to 1221444131377 its reverse (7731314441221), we get a palindrome (8952758572598).

The spelling of 1221444131377 in words is "one trillion, two hundred twenty-one billion, four hundred forty-four million, one hundred thirty-one thousand, three hundred seventy-seven".