16691197 has 2 divisors, whose sum is σ = 16691198. Its totient is φ = 16691196.

The previous prime is 16691183. The next prime is 16691221. The reversal of 16691197 is 79119661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10310521 + 6380676 = 3211^2 + 2526^2 .

It is a cyclic number.

It is not a de Polignac number, because 16691197 - 2⁷ = 16691069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16691137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8345598 + 8345599.

It is an arithmetic number, because the mean of its divisors is an integer number (8345599).

Almost surely, 2^16691197 is an apocalyptic number.

It is an amenable number.

16691197 is a deficient number, since it is larger than the sum of its proper divisors (1).

16691197 is an equidigital number, since it uses as much as digits as its factorization.

16691197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20412, while the sum is 40.

The square root of 16691197 is about 4085.4861399838. The cubic root of 16691197 is about 255.5617348712.

The spelling of 16691197 in words is "sixteen million, six hundred ninety-one thousand, one hundred ninety-seven".