16200821 has 24 divisors (see below), whose sum is σ = 21019320. Its totient is φ = 12362112.

The previous prime is 16200799. The next prime is 16200829. The reversal of 16200821 is 12800261.

It can be written as a sum of positive squares in 4 ways, for example, as 2436721 + 13764100 = 1561^2 + 3710^2 .

It is not a de Polignac number, because 16200821 - 2⁶ = 16200757 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16200793 and 16200802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16200829) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18035 + ... + 18911.

It is an arithmetic number, because the mean of its divisors is an integer number (875805).

Almost surely, 2^16200821 is an apocalyptic number.

It is an amenable number.

16200821 is a deficient number, since it is larger than the sum of its proper divisors (4818499).

16200821 is a wasteful number, since it uses less digits than its factorization.

16200821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933 (or 926 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 16200821 is about 4025.0243477524. The cubic root of 16200821 is about 253.0340739518.

The spelling of 16200821 in words is "sixteen million, two hundred thousand, eight hundred twenty-one".