6939509 has 2 divisors, whose sum is σ = 6939510. Its totient is φ = 6939508.

The previous prime is 6939487. The next prime is 6939511. The reversal of 6939509 is 9059396.

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., 4937284 + 2002225 = 2222^2 + 1415^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6939509 is a prime.

It is a super-3 number, since 3×6939509³ (a number of 22 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 6939511, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6939529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3469754 + 3469755.

It is an arithmetic number, because the mean of its divisors is an integer number (3469755).

Almost surely, 2^6939509 is an apocalyptic number.

It is an amenable number.

6939509 is a deficient number, since it is larger than the sum of its proper divisors (1).

6939509 is an equidigital number, since it uses as much as digits as its factorization.

6939509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 65610, while the sum is 41.

The square root of 6939509 is about 2634.2947822899. The cubic root of 6939509 is about 190.7404989923.

The spelling of 6939509 in words is "six million, nine hundred thirty-nine thousand, five hundred nine".