621505 has 4 divisors (see below), whose sum is σ = 745812. Its totient is φ = 497200.

The previous prime is 621473. The next prime is 621521. The reversal of 621505 is 505126.

It is a happy number.

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 419904 + 201601 = 648^2 + 449^2 .

It is not a de Polignac number, because 621505 - 2⁵ = 621473 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 62146 + ... + 62155.

It is an arithmetic number, because the mean of its divisors is an integer number (186453).

2⁶²¹⁵⁰⁵ is an apocalyptic number.

It is an amenable number.

621505 is a deficient number, since it is larger than the sum of its proper divisors (124307).

621505 is a wasteful number, since it uses less digits than its factorization.

621505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124306.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 621505 is about 788.3558841031. The cubic root of 621505 is about 85.3391295840.

The spelling of 621505 in words is "six hundred twenty-one thousand, five hundred five".