16651213 has 4 divisors (see below), whose sum is σ = 16660188. Its totient is φ = 16642240.

The previous prime is 16651199. The next prime is 16651237. The reversal of 16651213 is 31215661.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 10876804 + 5774409 = 3298^2 + 2403^2 .

It is a cyclic number.

It is not a de Polignac number, because 16651213 - 2⁵ = 16651181 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 (16651253) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 556 + ... + 5797.

It is an arithmetic number, because the mean of its divisors is an integer number (4165047).

Almost surely, 2^16651213 is an apocalyptic number.

It is an amenable number.

16651213 is a deficient number, since it is larger than the sum of its proper divisors (8975).

16651213 is an equidigital number, since it uses as much as digits as its factorization.

16651213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8974.

The product of its digits is 1080, while the sum is 25.

The square root of 16651213 is about 4080.5897858030. The cubic root of 16651213 is about 255.3575044475.

Adding to 16651213 its reverse (31215661), we get a palindrome (47866874).

The spelling of 16651213 in words is "sixteen million, six hundred fifty-one thousand, two hundred thirteen".