16681597 has 2 divisors, whose sum is σ = 16681598. Its totient is φ = 16681596.

The previous prime is 16681579. The next prime is 16681633. The reversal of 16681597 is 79518661.

It is a happy number.

Together with previous prime (16681579) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16475481 + 206116 = 4059^2 + 454^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16681597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16681507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8340798 + 8340799.

It is an arithmetic number, because the mean of its divisors is an integer number (8340799).

Almost surely, 2^16681597 is an apocalyptic number.

It is an amenable number.

16681597 is a deficient number, since it is larger than the sum of its proper divisors (1).

16681597 is an equidigital number, since it uses as much as digits as its factorization.

16681597 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 43.

The square root of 16681597 is about 4084.3110802190. The cubic root of 16681597 is about 255.5127297347.

The spelling of 16681597 in words is "sixteen million, six hundred eighty-one thousand, five hundred ninety-seven".