16545421 has 2 divisors, whose sum is σ = 16545422. Its totient is φ = 16545420.

The previous prime is 16545379. The next prime is 16545443. The reversal of 16545421 is 12454561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16281225 + 264196 = 4035^2 + 514^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16545421 is a prime.

It is a Chen prime.

It is equal to p_1063909 and since 16545421 and 1063909 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16545421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16545481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8272710 + 8272711.

It is an arithmetic number, because the mean of its divisors is an integer number (8272711).

Almost surely, 2^16545421 is an apocalyptic number.

It is an amenable number.

16545421 is a deficient number, since it is larger than the sum of its proper divisors (1).

16545421 is an equidigital number, since it uses as much as digits as its factorization.

16545421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4800, while the sum is 28.

The square root of 16545421 is about 4067.6062985496. The cubic root of 16545421 is about 254.8155580257.

Adding to 16545421 its reverse (12454561), we get a palindrome (28999982).

The spelling of 16545421 in words is "sixteen million, five hundred forty-five thousand, four hundred twenty-one".