620409 has 4 divisors (see below), whose sum is σ = 827216. Its totient is φ = 413604.

The previous prime is 620401. The next prime is 620413. The reversal of 620409 is 904026.

620409 is nontrivially palindromic in base 16.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 620409 - 2³ = 620401 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (620401) 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 in 3 ways as a sum of consecutive naturals, for example, 103399 + ... + 103404.

It is an arithmetic number, because the mean of its divisors is an integer number (206804).

2⁶²⁰⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

620409 is a deficient number, since it is larger than the sum of its proper divisors (206807).

620409 is a wasteful number, since it uses less digits than its factorization.

620409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206806.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 620409 is about 787.6604598429. The cubic root of 620409 is about 85.2889359842.

The spelling of 620409 in words is "six hundred twenty thousand, four hundred nine".