6691397 has 2 divisors, whose sum is σ = 6691398. Its totient is φ = 6691396.

The previous prime is 6691369. The next prime is 6691403. The reversal of 6691397 is 7931966.

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., 4879681 + 1811716 = 2209^2 + 1346^2 .

It is a cyclic number.

It is not a de Polignac number, because 6691397 - 2¹⁰ = 6690373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6691337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3345698 + 3345699.

It is an arithmetic number, because the mean of its divisors is an integer number (3345699).

Almost surely, 2^6691397 is an apocalyptic number.

It is an amenable number.

6691397 is a deficient number, since it is larger than the sum of its proper divisors (1).

6691397 is an equidigital number, since it uses as much as digits as its factorization.

6691397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 61236, while the sum is 41.

The square root of 6691397 is about 2586.7734728808. The cubic root of 6691397 is about 188.4396399507.

The spelling of 6691397 in words is "six million, six hundred ninety-one thousand, three hundred ninety-seven".