6686157509 has 2 divisors, whose sum is σ = 6686157510. Its totient is φ = 6686157508.

The previous prime is 6686157503. The next prime is 6686157547. The reversal of 6686157509 is 9057516866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6682245025 + 3912484 = 81745^2 + 1978^2 .

It is a cyclic number.

It is not a de Polignac number, because 6686157509 - 2⁴ = 6686157493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6686157503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3343078754 + 3343078755.

It is an arithmetic number, because the mean of its divisors is an integer number (3343078755).

Almost surely, 2^6686157509 is an apocalyptic number.

It is an amenable number.

6686157509 is a deficient number, since it is larger than the sum of its proper divisors (1).

6686157509 is an equidigital number, since it uses as much as digits as its factorization.

6686157509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2721600, while the sum is 53.

The square root of 6686157509 is about 81768.9275275150. The cubic root of 6686157509 is about 1883.9044316819.

The spelling of 6686157509 in words is "six billion, six hundred eighty-six million, one hundred fifty-seven thousand, five hundred nine".