621813 has 8 divisors (see below), whose sum is σ = 872800. Its totient is φ = 392688.

The previous prime is 621799. The next prime is 621821. The reversal of 621813 is 318126.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 621813 - 2⁶ = 621749 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 621813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621833) 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 7 ways as a sum of consecutive naturals, for example, 5398 + ... + 5511.

It is an arithmetic number, because the mean of its divisors is an integer number (109100).

2⁶²¹⁸¹³ is an apocalyptic number.

It is an amenable number.

621813 is a deficient number, since it is larger than the sum of its proper divisors (250987).

621813 is a wasteful number, since it uses less digits than its factorization.

621813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10931.

The product of its digits is 288, while the sum is 21.

The square root of 621813 is about 788.5512031568. The cubic root of 621813 is about 85.3532244619.

Adding to 621813 its reverse (318126), we get a palindrome (939939).

The spelling of 621813 in words is "six hundred twenty-one thousand, eight hundred thirteen".