16821125 has 16 divisors (see below), whose sum is σ = 21566064. Its totient is φ = 13089600.

The previous prime is 16821121. The next prime is 16821139. The reversal of 16821125 is 52112861.

It can be written as a sum of positive squares in 8 ways, for example, as 6791236 + 10029889 = 2606^2 + 3167^2 .

It is not a de Polignac number, because 16821125 - 2² = 16821121 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 16821094 and 16821103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16821121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2807 + ... + 6443.

It is an arithmetic number, because the mean of its divisors is an integer number (1347879).

Almost surely, 2^16821125 is an apocalyptic number.

It is an amenable number.

16821125 is a deficient number, since it is larger than the sum of its proper divisors (4744939).

16821125 is an equidigital number, since it uses as much as digits as its factorization.

16821125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3689 (or 3679 counting only the distinct ones).

The product of its digits is 960, while the sum is 26.

The square root of 16821125 is about 4101.3564829212. The cubic root of 16821125 is about 256.2231381718.

Adding to 16821125 its reverse (52112861), we get a palindrome (68933986).

The spelling of 16821125 in words is "sixteen million, eight hundred twenty-one thousand, one hundred twenty-five".