1231423355501 has 2 divisors, whose sum is σ = 1231423355502. Its totient is φ = 1231423355500.

The previous prime is 1231423355443. The next prime is 1231423355521. The reversal of 1231423355501 is 1055533241321.

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., 743563014601 + 487860340900 = 862301^2 + 698470^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231423355501 - 2¹⁰ = 1231423354477 is a prime.

It is a super-2 number, since 2×1231423355501² (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 (1231423355521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615711677750 + 615711677751.

It is an arithmetic number, because the mean of its divisors is an integer number (615711677751).

Almost surely, 2^{1231423355501} is an apocalyptic number.

It is an amenable number.

1231423355501 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231423355501 is an equidigital number, since it uses as much as digits as its factorization.

1231423355501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54000, while the sum is 35.

Adding to 1231423355501 its reverse (1055533241321), we get a palindrome (2286956596822).

The spelling of 1231423355501 in words is "one trillion, two hundred thirty-one billion, four hundred twenty-three million, three hundred fifty-five thousand, five hundred one".