126643668517 has 2 divisors, whose sum is σ = 126643668518. Its totient is φ = 126643668516.

The previous prime is 126643668467. The next prime is 126643668527. The reversal of 126643668517 is 715866346621.

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., 120205050436 + 6438618081 = 346706^2 + 80241^2 .

It is a cyclic number.

It is not a de Polignac number, because 126643668517 - 2¹⁵ = 126643635749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (126643668527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63321834258 + 63321834259.

It is an arithmetic number, because the mean of its divisors is an integer number (63321834259).

Almost surely, 2^126643668517 is an apocalyptic number.

It is an amenable number.

126643668517 is a deficient number, since it is larger than the sum of its proper divisors (1).

126643668517 is an equidigital number, since it uses as much as digits as its factorization.

126643668517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8709120, while the sum is 55.

The spelling of 126643668517 in words is "one hundred twenty-six billion, six hundred forty-three million, six hundred sixty-eight thousand, five hundred seventeen".