621220 has 24 divisors (see below), whose sum is σ = 1323000. Its totient is φ = 244992.

The previous prime is 621217. The next prime is 621223. The reversal of 621220 is 22126.

It is a happy number.

621220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (621217) and next prime (621223).

It can be written as a sum of positive squares in 4 ways, for example, as 46656 + 574564 = 216^2 + 758^2 .

It is an Ulam number.

It is a plaindrome in base 14.

It is a self number, because there is not a number n which added to its sum of digits gives 621220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1606 + ... + 1954.

It is an arithmetic number, because the mean of its divisors is an integer number (55125).

2⁶²¹²²⁰ is an apocalyptic number.

It is an amenable number.

621220 is an abundant number, since it is smaller than the sum of its proper divisors (701780).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

621220 is a wasteful number, since it uses less digits than its factorization.

621220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447 (or 445 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 621220 is about 788.1751074476. The cubic root of 621220 is about 85.3260830971.

Adding to 621220 its reverse (22126), we get a palindrome (643346).

It can be divided in two parts, 621 and 220, that added together give a square (841 = 29²).

The spelling of 621220 in words is "six hundred twenty-one thousand, two hundred twenty".