16644553 has 2 divisors, whose sum is σ = 16644554. Its totient is φ = 16644552.

The previous prime is 16644539. The next prime is 16644557. The reversal of 16644553 is 35544661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13155129 + 3489424 = 3627^2 + 1868^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16644553 is a prime.

It is a super-2 number, since 2×16644553² = 554082289139618, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16644557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8322276 + 8322277.

It is an arithmetic number, because the mean of its divisors is an integer number (8322277).

Almost surely, 2^16644553 is an apocalyptic number.

It is an amenable number.

16644553 is a deficient number, since it is larger than the sum of its proper divisors (1).

16644553 is an equidigital number, since it uses as much as digits as its factorization.

16644553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43200, while the sum is 34.

The square root of 16644553 is about 4079.7736456818. The cubic root of 16644553 is about 255.3234547205.

The spelling of 16644553 in words is "sixteen million, six hundred forty-four thousand, five hundred fifty-three".