620905 has 4 divisors (see below), whose sum is σ = 745092. Its totient is φ = 496720.

The previous prime is 620887. The next prime is 620909. The reversal of 620905 is 509026.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 434281 + 186624 = 659^2 + 432^2 .

It is not a de Polignac number, because 620905 - 2⁷ = 620777 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (620909) 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, 62086 + ... + 62095.

It is an arithmetic number, because the mean of its divisors is an integer number (186273).

2⁶²⁰⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

620905 is a deficient number, since it is larger than the sum of its proper divisors (124187).

620905 is a wasteful number, since it uses less digits than its factorization.

620905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124186.

The product of its (nonzero) digits is 540, while the sum is 22.

The square root of 620905 is about 787.9752534185. The cubic root of 620905 is about 85.3116586525.

The spelling of 620905 in words is "six hundred twenty thousand, nine hundred five".