16445521 has 2 divisors, whose sum is σ = 16445522. Its totient is φ = 16445520.

The previous prime is 16445519. The next prime is 16445549. The reversal of 16445521 is 12554461.

It is an a-pointer prime, because the next prime (16445549) can be obtained adding 16445521 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10857025 + 5588496 = 3295^2 + 2364^2 .

It is an emirp because it is prime and its reverse (12554461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16445521 - 2¹ = 16445519 is a prime.

It is a super-2 number, since 2×16445521² = 540910321922882, which contains 22 as substring.

Together with 16445519, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 16445521.

It is not a weakly prime, because it can be changed into another prime (16440521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8222760 + 8222761.

It is an arithmetic number, because the mean of its divisors is an integer number (8222761).

Almost surely, 2^16445521 is an apocalyptic number.

It is an amenable number.

16445521 is a deficient number, since it is larger than the sum of its proper divisors (1).

16445521 is an equidigital number, since it uses as much as digits as its factorization.

16445521 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 16445521 is about 4055.3077565087. The cubic root of 16445521 is about 254.3016700090.

Adding to 16445521 its reverse (12554461), we get a palindrome (28999982).

The spelling of 16445521 in words is "sixteen million, four hundred forty-five thousand, five hundred twenty-one".