16554421 has 4 divisors (see below), whose sum is σ = 17827852. Its totient is φ = 15280992.

The previous prime is 16554407. The next prime is 16554437. The reversal of 16554421 is 12445561.

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

It can be written as a sum of positive squares in 2 ways, for example, as 864900 + 15689521 = 930^2 + 3961^2 .

It is a cyclic number.

It is not a de Polignac number, because 16554421 - 2¹⁵ = 16521653 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16554421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16554401) 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, 636696 + ... + 636721.

It is an arithmetic number, because the mean of its divisors is an integer number (4456963).

Almost surely, 2^16554421 is an apocalyptic number.

It is an amenable number.

16554421 is a deficient number, since it is larger than the sum of its proper divisors (1273431).

16554421 is a wasteful number, since it uses less digits than its factorization.

16554421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1273430.

The product of its digits is 4800, while the sum is 28.

The square root of 16554421 is about 4068.7124499035. The cubic root of 16554421 is about 254.8617525654.

Adding to 16554421 its reverse (12445561), we get a palindrome (28999982).

The spelling of 16554421 in words is "sixteen million, five hundred fifty-four thousand, four hundred twenty-one".