1231501434557 has 2 divisors, whose sum is σ = 1231501434558. Its totient is φ = 1231501434556.

The previous prime is 1231501434509. The next prime is 1231501434577. The reversal of 1231501434557 is 7554341051321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 836540719876 + 394960714681 = 914626^2 + 628459^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231501434557 - 2¹² = 1231501430461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231501434577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615750717278 + 615750717279.

It is an arithmetic number, because the mean of its divisors is an integer number (615750717279).

Almost surely, 2^{1231501434557} is an apocalyptic number.

It is an amenable number.

1231501434557 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231501434557 is an equidigital number, since it uses as much as digits as its factorization.

1231501434557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252000, while the sum is 41.

Adding to 1231501434557 its reverse (7554341051321), we get a palindrome (8785842485878).

The spelling of 1231501434557 in words is "one trillion, two hundred thirty-one billion, five hundred one million, four hundred thirty-four thousand, five hundred fifty-seven".