1231310201221 has 2 divisors, whose sum is σ = 1231310201222. Its totient is φ = 1231310201220.

The previous prime is 1231310201213. The next prime is 1231310201227. The reversal of 1231310201221 is 1221020131321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 696782520225 + 534527680996 = 834735^2 + 731114^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231310201221 - 2³ = 1231310201213 is a prime.

It is a super-2 number, since 2×1231310201221² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231310201227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615655100610 + 615655100611.

It is an arithmetic number, because the mean of its divisors is an integer number (615655100611).

Almost surely, 2^{1231310201221} is an apocalyptic number.

It is an amenable number.

1231310201221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231310201221 is an equidigital number, since it uses as much as digits as its factorization.

1231310201221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 1231310201221 its reverse (1221020131321), we get a palindrome (2452330332542).

The spelling of 1231310201221 in words is "one trillion, two hundred thirty-one billion, three hundred ten million, two hundred one thousand, two hundred twenty-one".