16645553 has 2 divisors, whose sum is σ = 16645554. Its totient is φ = 16645552.

The previous prime is 16645513. The next prime is 16645561. The reversal of 16645553 is 35554661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15547249 + 1098304 = 3943^2 + 1048^2 .

It is a cyclic number.

It is not a de Polignac number, because 16645553 - 2¹⁶ = 16580017 is a prime.

It is not a weakly prime, because it can be changed into another prime (16645513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8322776 + 8322777.

It is an arithmetic number, because the mean of its divisors is an integer number (8322777).

Almost surely, 2^16645553 is an apocalyptic number.

It is an amenable number.

16645553 is a deficient number, since it is larger than the sum of its proper divisors (1).

16645553 is an equidigital number, since it uses as much as digits as its factorization.

16645553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54000, while the sum is 35.

The square root of 16645553 is about 4079.8961996600. The cubic root of 16645553 is about 255.3285678715.

The spelling of 16645553 in words is "sixteen million, six hundred forty-five thousand, five hundred fifty-three".