620818609 has 2 divisors, whose sum is σ = 620818610. Its totient is φ = 620818608.

The previous prime is 620818607. The next prime is 620818621. The reversal of 620818609 is 906818026.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 616429584 + 4389025 = 24828^2 + 2095^2 .

It is a cyclic number.

It is not a de Polignac number, because 620818609 - 2¹ = 620818607 is a prime.

Together with 620818607, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (620818603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310409304 + 310409305.

It is an arithmetic number, because the mean of its divisors is an integer number (310409305).

Almost surely, 2^620818609 is an apocalyptic number.

It is an amenable number.

620818609 is a deficient number, since it is larger than the sum of its proper divisors (1).

620818609 is an equidigital number, since it uses as much as digits as its factorization.

620818609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 620818609 is about 24916.2318379004. The cubic root of 620818609 is about 853.0770179314.

The spelling of 620818609 in words is "six hundred twenty million, eight hundred eighteen thousand, six hundred nine".