620648238209 has 4 divisors (see below), whose sum is σ = 621008872260. Its totient is φ = 620287604160.

The previous prime is 620648238191. The next prime is 620648238257. The reversal of 620648238209 is 902832846026.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 902832846026 = 2 ⋅451416423013.

It can be written as a sum of positive squares in 2 ways, for example, as 219630010609 + 401018227600 = 468647^2 + 633260^2 .

It is a cyclic number.

It is not a de Polignac number, because 620648238209 - 2⁸ = 620648237953 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (620648231209) 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 in 3 ways as a sum of consecutive naturals, for example, 180314444 + ... + 180317885.

It is an arithmetic number, because the mean of its divisors is an integer number (155252218065).

Almost surely, 2^620648238209 is an apocalyptic number.

It is an amenable number.

620648238209 is a deficient number, since it is larger than the sum of its proper divisors (360634051).

620648238209 is a wasteful number, since it uses less digits than its factorization.

620648238209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360634050.

The product of its (nonzero) digits is 1990656, while the sum is 50.

The spelling of 620648238209 in words is "six hundred twenty billion, six hundred forty-eight million, two hundred thirty-eight thousand, two hundred nine".