16664551 has 2 divisors, whose sum is σ = 16664552. Its totient is φ = 16664550.

The previous prime is 16664519. The next prime is 16664561. The reversal of 16664551 is 15546661.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16664551 - 2⁵ = 16664519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16664561) 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, 8332275 + 8332276.

It is an arithmetic number, because the mean of its divisors is an integer number (8332276).

Almost surely, 2^16664551 is an apocalyptic number.

16664551 is a deficient number, since it is larger than the sum of its proper divisors (1).

16664551 is an equidigital number, since it uses as much as digits as its factorization.

16664551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21600, while the sum is 34.

The square root of 16664551 is about 4082.2237812251. The cubic root of 16664551 is about 255.4256686383.

The spelling of 16664551 in words is "sixteen million, six hundred sixty-four thousand, five hundred fifty-one".