16551623 has 4 divisors (see below), whose sum is σ = 18056328. Its totient is φ = 15046920.

The previous prime is 16551599. The next prime is 16551629. The reversal of 16551623 is 32615561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16551623 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 (16551629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 752336 + ... + 752357.

It is an arithmetic number, because the mean of its divisors is an integer number (4514082).

Almost surely, 2^16551623 is an apocalyptic number.

16551623 is a deficient number, since it is larger than the sum of its proper divisors (1504705).

16551623 is a wasteful number, since it uses less digits than its factorization.

16551623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1504704.

The product of its digits is 5400, while the sum is 29.

The square root of 16551623 is about 4068.3685919543. The cubic root of 16551623 is about 254.8473929901.

The spelling of 16551623 in words is "sixteen million, five hundred fifty-one thousand, six hundred twenty-three".