16898221 has 4 divisors (see below), whose sum is σ = 17892252. Its totient is φ = 15904192.

The previous prime is 16898207. The next prime is 16898267. The reversal of 16898221 is 12289861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12289861 = 17 ⋅722933.

It can be written as a sum of positive squares in 2 ways, for example, as 15888196 + 1010025 = 3986^2 + 1005^2 .

It is a cyclic number.

It is not a de Polignac number, because 16898221 - 2¹⁹ = 16373933 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 (16898621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 496990 + ... + 497023.

It is an arithmetic number, because the mean of its divisors is an integer number (4473063).

Almost surely, 2^16898221 is an apocalyptic number.

It is an amenable number.

16898221 is a deficient number, since it is larger than the sum of its proper divisors (994031).

16898221 is an equidigital number, since it uses as much as digits as its factorization.

16898221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994030.

The product of its digits is 13824, while the sum is 37.

The square root of 16898221 is about 4110.7445797568. The cubic root of 16898221 is about 256.6139894893.

It can be divided in two parts, 168 and 98221, that added together give a palindrome (98389).

The spelling of 16898221 in words is "sixteen million, eight hundred ninety-eight thousand, two hundred twenty-one".