13820621 has 2 divisors, whose sum is σ = 13820622. Its totient is φ = 13820620.

The previous prime is 13820603. The next prime is 13820623. The reversal of 13820621 is 12602831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10530025 + 3290596 = 3245^2 + 1814^2 .

It is a cyclic number.

It is not a de Polignac number, because 13820621 - 2¹⁴ = 13804237 is a prime.

Together with 13820623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13820623) 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, 6910310 + 6910311.

It is an arithmetic number, because the mean of its divisors is an integer number (6910311).

Almost surely, 2^13820621 is an apocalyptic number.

It is an amenable number.

13820621 is a deficient number, since it is larger than the sum of its proper divisors (1).

13820621 is an equidigital number, since it uses as much as digits as its factorization.

13820621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 13820621 is about 3717.6095814381. The cubic root of 13820621 is about 239.9804440084.

It can be divided in two parts, 13820 and 621, that added together give a palindrome (14441).

The spelling of 13820621 in words is "thirteen million, eight hundred twenty thousand, six hundred twenty-one".