16612021 has 2 divisors, whose sum is σ = 16612022. Its totient is φ = 16612020.

The previous prime is 16611989. The next prime is 16612027. The reversal of 16612021 is 12021661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12327121 + 4284900 = 3511^2 + 2070^2 .

It is a cyclic number.

It is not a de Polignac number, because 16612021 - 2⁵ = 16611989 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16612021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16612027) 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, 8306010 + 8306011.

It is an arithmetic number, because the mean of its divisors is an integer number (8306011).

Almost surely, 2^16612021 is an apocalyptic number.

It is an amenable number.

16612021 is a deficient number, since it is larger than the sum of its proper divisors (1).

16612021 is an equidigital number, since it uses as much as digits as its factorization.

16612021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 16612021 is about 4075.7847097216. The cubic root of 16612021 is about 255.1570018670.

Adding to 16612021 its reverse (12021661), we get a palindrome (28633682).

The spelling of 16612021 in words is "sixteen million, six hundred twelve thousand, twenty-one".