16646449 has 2 divisors, whose sum is σ = 16646450. Its totient is φ = 16646448.

The previous prime is 16646431. The next prime is 16646453. The reversal of 16646449 is 94464661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16646400 + 49 = 4080^2 + 7^2 .

It is a cyclic number.

It is not a de Polignac number, because 16646449 - 2²³ = 8257841 is a prime.

It is equal to p_1069987 and since 16646449 and 1069987 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (16646479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is an upside-down number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8323224 + 8323225.

It is an arithmetic number, because the mean of its divisors is an integer number (8323225).

Almost surely, 2^16646449 is an apocalyptic number.

It is an amenable number.

16646449 is a deficient number, since it is larger than the sum of its proper divisors (1).

16646449 is an equidigital number, since it uses as much as digits as its factorization.

16646449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 40.

The square root of 16646449 is about 4080.0060048975. The cubic root of 16646449 is about 255.3331490810. Note that the first 3 decimals are identical.

It can be divided in two parts, 166464 and 49, that multiplied together give a square (8156736 = 2856²).

The spelling of 16646449 in words is "sixteen million, six hundred forty-six thousand, four hundred forty-nine".