16725809 has 2 divisors, whose sum is σ = 16725810. Its totient is φ = 16725808.

The previous prime is 16725799. The next prime is 16725811. The reversal of 16725809 is 90852761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13104400 + 3621409 = 3620^2 + 1903^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16725809 is a prime.

Together with 16725811, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16725869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8362904 + 8362905.

It is an arithmetic number, because the mean of its divisors is an integer number (8362905).

Almost surely, 2^16725809 is an apocalyptic number.

It is an amenable number.

16725809 is a deficient number, since it is larger than the sum of its proper divisors (1).

16725809 is an equidigital number, since it uses as much as digits as its factorization.

16725809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 16725809 is about 4089.7199170603. The cubic root of 16725809 is about 255.7382629655.

The spelling of 16725809 in words is "sixteen million, seven hundred twenty-five thousand, eight hundred nine".