6689691 has 36 divisors (see below), whose sum is σ = 10698480. Its totient is φ = 4021920.

The previous prime is 6689689. The next prime is 6689699. The reversal of 6689691 is 1969866.

It is not a de Polignac number, because 6689691 - 2¹ = 6689689 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

Its product of digits (139968) is a multiple of the sum of its prime factors (144).

6689691 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6689699) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 94186 + ... + 94256.

It is an arithmetic number, because the mean of its divisors is an integer number (297180).

Almost surely, 2^6689691 is an apocalyptic number.

6689691 is a deficient number, since it is larger than the sum of its proper divisors (4008789).

6689691 is a wasteful number, since it uses less digits than its factorization.

6689691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 122 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 6689691 is about 2586.4436974348. The cubic root of 6689691 is about 188.4236240948.

The spelling of 6689691 in words is "six million, six hundred eighty-nine thousand, six hundred ninety-one".