621559 has 4 divisors (see below), whose sum is σ = 630904. Its totient is φ = 612216.

The previous prime is 621541. The next prime is 621583. The reversal of 621559 is 955126.

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

It is a cyclic number.

It is not a de Polignac number, because 621559 - 2⁵ = 621527 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621059) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4572 + ... + 4705.

It is an arithmetic number, because the mean of its divisors is an integer number (157726).

2⁶²¹⁵⁵⁹ is an apocalyptic number.

621559 is a deficient number, since it is larger than the sum of its proper divisors (9345).

621559 is an equidigital number, since it uses as much as digits as its factorization.

621559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9344.

The product of its digits is 2700, while the sum is 28.

The square root of 621559 is about 788.3901318510. The cubic root of 621559 is about 85.3416011005.

The spelling of 621559 in words is "six hundred twenty-one thousand, five hundred fifty-nine".