1251542140217 has 2 divisors, whose sum is σ = 1251542140218. Its totient is φ = 1251542140216.

The previous prime is 1251542140187. The next prime is 1251542140237. The reversal of 1251542140217 is 7120412451521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 631549679401 + 619992460816 = 794701^2 + 787396^2 .

It is a cyclic number.

It is not a de Polignac number, because 1251542140217 - 2¹⁰ = 1251542139193 is a prime.

It is not a weakly prime, because it can be changed into another prime (1251542140237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625771070108 + 625771070109.

It is an arithmetic number, because the mean of its divisors is an integer number (625771070109).

Almost surely, 2^{1251542140217} is an apocalyptic number.

It is an amenable number.

1251542140217 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251542140217 is an equidigital number, since it uses as much as digits as its factorization.

1251542140217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22400, while the sum is 35.

Adding to 1251542140217 its reverse (7120412451521), we get a palindrome (8371954591738).

The spelling of 1251542140217 in words is "one trillion, two hundred fifty-one billion, five hundred forty-two million, one hundred forty thousand, two hundred seventeen".