6687869 has 2 divisors, whose sum is σ = 6687870. Its totient is φ = 6687868.

The previous prime is 6687853. The next prime is 6687881. The reversal of 6687869 is 9687866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3667225 + 3020644 = 1915^2 + 1738^2 .

It is a cyclic number.

It is not a de Polignac number, because 6687869 - 2⁴ = 6687853 is a prime.

It is a super-2 number, since 2×6687869² = 89455183522322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6687809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3343934 + 3343935.

It is an arithmetic number, because the mean of its divisors is an integer number (3343935).

Almost surely, 2^6687869 is an apocalyptic number.

It is an amenable number.

6687869 is a deficient number, since it is larger than the sum of its proper divisors (1).

6687869 is an equidigital number, since it uses as much as digits as its factorization.

6687869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 50.

The square root of 6687869 is about 2586.0914523659. The cubic root of 6687869 is about 188.4065162286.

It can be divided in two parts, 6 and 687869, that multiplied together give a palindrome (4127214).

The spelling of 6687869 in words is "six million, six hundred eighty-seven thousand, eight hundred sixty-nine".