16518821 has 8 divisors (see below), whose sum is σ = 18249600. Its totient is φ = 14826240.

The previous prime is 16518811. The next prime is 16518823. The reversal of 16518821 is 12881561.

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

It is not a de Polignac number, because 16518821 - 2¹⁰ = 16517797 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16518823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8636 + ... + 10373.

It is an arithmetic number, because the mean of its divisors is an integer number (2281200).

Almost surely, 2^16518821 is an apocalyptic number.

16518821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16518821 is a deficient number, since it is larger than the sum of its proper divisors (1730779).

16518821 is a wasteful number, since it uses less digits than its factorization.

16518821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19099.

The product of its digits is 3840, while the sum is 32.

The square root of 16518821 is about 4064.3352469992. The cubic root of 16518821 is about 254.6789294994.

The spelling of 16518821 in words is "sixteen million, five hundred eighteen thousand, eight hundred twenty-one".