621217220 has 24 divisors (see below), whose sum is σ = 1404907224. Its totient is φ = 229372416.

The previous prime is 621217183. The next prime is 621217249. The reversal of 621217220 is 22712126.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 19201924 + 602015296 = 4382^2 + 24536^2 .

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 7 ways as a sum of consecutive naturals, for example, 1194389 + ... + 1194908.

It is an arithmetic number, because the mean of its divisors is an integer number (58537801).

Almost surely, 2^621217220 is an apocalyptic number.

It is an amenable number.

621217220 is an abundant number, since it is smaller than the sum of its proper divisors (783690004).

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

621217220 is a wasteful number, since it uses less digits than its factorization.

621217220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2389319 (or 2389317 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 621217220 is about 24924.2295768595. The cubic root of 621217220 is about 853.2595581700.

Adding to 621217220 its reverse (22712126), we get a palindrome (643929346).

It can be divided in two parts, 6212 and 17220, that added together give a palindrome (23432).

The spelling of 621217220 in words is "six hundred twenty-one million, two hundred seventeen thousand, two hundred twenty".