620513809 has 2 divisors, whose sum is σ = 620513810. Its totient is φ = 620513808.

The previous prime is 620513713. The next prime is 620513833. The reversal of 620513809 is 908315026.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 386515600 + 233998209 = 19660^2 + 15297^2 .

It is a cyclic number.

It is not a de Polignac number, because 620513809 - 2¹⁵ = 620481041 is a prime.

It is not a weakly prime, because it can be changed into another prime (620511809) 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, 310256904 + 310256905.

It is an arithmetic number, because the mean of its divisors is an integer number (310256905).

Almost surely, 2^620513809 is an apocalyptic number.

It is an amenable number.

620513809 is a deficient number, since it is larger than the sum of its proper divisors (1).

620513809 is an equidigital number, since it uses as much as digits as its factorization.

620513809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 620513809 is about 24910.1145922695. The cubic root of 620513809 is about 852.9373848534.

The spelling of 620513809 in words is "six hundred twenty million, five hundred thirteen thousand, eight hundred nine".