620644289 has 2 divisors, whose sum is σ = 620644290. Its totient is φ = 620644288.

The previous prime is 620644267. The next prime is 620644307. The reversal of 620644289 is 982446026.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 324288064 + 296356225 = 18008^2 + 17215^2 .

It is a cyclic number.

It is not a de Polignac number, because 620644289 - 2⁸ = 620644033 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (620644229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310322144 + 310322145.

It is an arithmetic number, because the mean of its divisors is an integer number (310322145).

Almost surely, 2^620644289 is an apocalyptic number.

It is an amenable number.

620644289 is a deficient number, since it is larger than the sum of its proper divisors (1).

620644289 is an equidigital number, since it uses as much as digits as its factorization.

620644289 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 165888, while the sum is 41.

The square root of 620644289 is about 24912.7334710585. The cubic root of 620644289 is about 852.9971651347.

The spelling of 620644289 in words is "six hundred twenty million, six hundred forty-four thousand, two hundred eighty-nine".