155220 has 48 divisors (see below), whose sum is σ = 470400. Its totient is φ = 38016.

The previous prime is 155219. The next prime is 155231. The reversal of 155220 is 22551.

155220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 155220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 681 + ... + 879.

It is an arithmetic number, because the mean of its divisors is an integer number (9800).

2¹⁵⁵²²⁰ is an apocalyptic number.

155220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 155220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (235200).

155220 is an abundant number, since it is smaller than the sum of its proper divisors (315180).

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

155220 is a wasteful number, since it uses less digits than its factorization.

155220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224 (or 222 counting only the distinct ones).

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

The square root of 155220 is about 393.9796949083. The cubic root of 155220 is about 53.7422559602.

Adding to 155220 its reverse (22551), we get a palindrome (177771).

The spelling of 155220 in words is "one hundred fifty-five thousand, two hundred twenty".