16661623 has 8 divisors (see below), whose sum is σ = 18213120. Its totient is φ = 15116280.

The previous prime is 16661599. The next prime is 16661629. The reversal of 16661623 is 32616661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16661623 - 2¹³ = 16653431 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16661629) 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 in 7 ways as a sum of consecutive naturals, for example, 5586 + ... + 8032.

It is an arithmetic number, because the mean of its divisors is an integer number (2276640).

Almost surely, 2^16661623 is an apocalyptic number.

16661623 is a deficient number, since it is larger than the sum of its proper divisors (1551497).

16661623 is a wasteful number, since it uses less digits than its factorization.

16661623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3077.

The product of its digits is 7776, while the sum is 31.

The square root of 16661623 is about 4081.8651374096. The cubic root of 16661623 is about 255.4107081360.

The spelling of 16661623 in words is "sixteen million, six hundred sixty-one thousand, six hundred twenty-three".