551220 has 24 divisors (see below), whose sum is σ = 1543584. Its totient is φ = 146976.

The previous prime is 551219. The next prime is 551231. The reversal of 551220 is 22155.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 551220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4534 + ... + 4653.

It is an arithmetic number, because the mean of its divisors is an integer number (64316).

2⁵⁵¹²²⁰ is an apocalyptic number.

It is an amenable number.

551220 is an abundant number, since it is smaller than the sum of its proper divisors (992364).

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

551220 is a wasteful number, since it uses less digits than its factorization.

551220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9199 (or 9197 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 15.

The square root of 551220 is about 742.4419169201. The cubic root of 551220 is about 81.9926624408.

Adding to 551220 its reverse (22155), we get a palindrome (573375).

It can be divided in two parts, 55 and 1220, that added together give a triangular number (1275 = T₅₀).

The spelling of 551220 in words is "five hundred fifty-one thousand, two hundred twenty".