20008621 has 2 divisors, whose sum is σ = 20008622. Its totient is φ = 20008620.

The previous prime is 20008607. The next prime is 20008649. The reversal of 20008621 is 12680002.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15760900 + 4247721 = 3970^2 + 2061^2 .

It is a cyclic number.

It is not a de Polignac number, because 20008621 - 2⁵ = 20008589 is a prime.

It is a Chen prime.

It is equal to p_1271125 and since 20008621 and 1271125 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20008721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10004310 + 10004311.

It is an arithmetic number, because the mean of its divisors is an integer number (10004311).

Almost surely, 2^20008621 is an apocalyptic number.

It is an amenable number.

20008621 is a deficient number, since it is larger than the sum of its proper divisors (1).

20008621 is an equidigital number, since it uses as much as digits as its factorization.

20008621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 20008621 is about 4473.0997082560. The cubic root of 20008621 is about 271.4807577141.

Adding to 20008621 its reverse (12680002), we get a palindrome (32688623).

The spelling of 20008621 in words is "twenty million, eight thousand, six hundred twenty-one".