8135129669 has 2 divisors, whose sum is σ = 8135129670. Its totient is φ = 8135129668.

The previous prime is 8135129659. The next prime is 8135129701. The reversal of 8135129669 is 9669215318.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6849548644 + 1285581025 = 82762^2 + 35855^2 .

It is a cyclic number.

It is not a de Polignac number, because 8135129669 - 2¹² = 8135125573 is a prime.

It is a super-2 number, since 2×8135129669² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8135129609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4067564834 + 4067564835.

It is an arithmetic number, because the mean of its divisors is an integer number (4067564835).

Almost surely, 2^8135129669 is an apocalyptic number.

It is an amenable number.

8135129669 is a deficient number, since it is larger than the sum of its proper divisors (1).

8135129669 is an equidigital number, since it uses as much as digits as its factorization.

8135129669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 699840, while the sum is 50.

The square root of 8135129669 is about 90194.9536781299. The cubic root of 8135129669 is about 2011.1979912318.

The spelling of 8135129669 in words is "eight billion, one hundred thirty-five million, one hundred twenty-nine thousand, six hundred sixty-nine".