621903 has 4 divisors (see below), whose sum is σ = 829208. Its totient is φ = 414600.

The previous prime is 621893. The next prime is 621913. The reversal of 621903 is 309126.

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

It is an interprime number because it is at equal distance from previous prime (621893) and next prime (621913).

It is not a de Polignac number, because 621903 - 2⁵ = 621871 is a prime.

It is a D-number.

It is a Duffinian number.

621903 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 621903.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621913) 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, 103648 + ... + 103653.

It is an arithmetic number, because the mean of its divisors is an integer number (207302).

2⁶²¹⁹⁰³ is an apocalyptic number.

621903 is a deficient number, since it is larger than the sum of its proper divisors (207305).

621903 is a wasteful number, since it uses less digits than its factorization.

621903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207304.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 621903 is about 788.6082677730. The cubic root of 621903 is about 85.3573422163.

The spelling of 621903 in words is "six hundred twenty-one thousand, nine hundred three".