16621013 has 2 divisors, whose sum is σ = 16621014. Its totient is φ = 16621012.

The previous prime is 16620983. The next prime is 16621021. The reversal of 16621013 is 31012661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16589329 + 31684 = 4073^2 + 178^2 .

It is a cyclic number.

It is not a de Polignac number, because 16621013 - 2¹⁴ = 16604629 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16621043) 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 as a sum of consecutive naturals, namely, 8310506 + 8310507.

It is an arithmetic number, because the mean of its divisors is an integer number (8310507).

Almost surely, 2^16621013 is an apocalyptic number.

It is an amenable number.

16621013 is a deficient number, since it is larger than the sum of its proper divisors (1).

16621013 is an equidigital number, since it uses as much as digits as its factorization.

16621013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 16621013 is about 4076.8876609492. The cubic root of 16621013 is about 255.2030319458.

Adding to 16621013 its reverse (31012661), we get a palindrome (47633674).

The spelling of 16621013 in words is "sixteen million, six hundred twenty-one thousand, thirteen".