16481821 has 4 divisors (see below), whose sum is σ = 16667100. Its totient is φ = 16296544.

The previous prime is 16481809. The next prime is 16481851. The reversal of 16481821 is 12818461.

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 11256025 + 5225796 = 3355^2 + 2286^2 .

It is a cyclic number.

It is not a de Polignac number, because 16481821 - 2⁷ = 16481693 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 (16481851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 92506 + ... + 92683.

It is an arithmetic number, because the mean of its divisors is an integer number (4166775).

Almost surely, 2^16481821 is an apocalyptic number.

It is an amenable number.

16481821 is a deficient number, since it is larger than the sum of its proper divisors (185279).

16481821 is an equidigital number, since it uses as much as digits as its factorization.

16481821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185278.

The product of its digits is 3072, while the sum is 31.

The square root of 16481821 is about 4059.7809054184. The cubic root of 16481821 is about 254.4886381811.

The spelling of 16481821 in words is "sixteen million, four hundred eighty-one thousand, eight hundred twenty-one".