16521213 has 16 divisors (see below), whose sum is σ = 23224320. Its totient is φ = 10430784.

The previous prime is 16521209. The next prime is 16521217. The reversal of 16521213 is 31212561.

It is an interprime number because it is at equal distance from previous prime (16521209) and next prime (16521217).

It is not a de Polignac number, because 16521213 - 2² = 16521209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16521213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16521217) 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 15 ways as a sum of consecutive naturals, for example, 2820 + ... + 6402.

It is an arithmetic number, because the mean of its divisors is an integer number (1451520).

Almost surely, 2^16521213 is an apocalyptic number.

It is an amenable number.

16521213 is a deficient number, since it is larger than the sum of its proper divisors (6703107).

16521213 is a wasteful number, since it uses less digits than its factorization.

16521213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3668.

The product of its digits is 360, while the sum is 21.

The square root of 16521213 is about 4064.6295034111. The cubic root of 16521213 is about 254.6912217931.

Adding to 16521213 its reverse (31212561), we get a palindrome (47733774).

The spelling of 16521213 in words is "sixteen million, five hundred twenty-one thousand, two hundred thirteen".