155540 has 48 divisors (see below), whose sum is σ = 411264. Its totient is φ = 48000.

The previous prime is 155539. The next prime is 155557. The reversal of 155540 is 45551.

It is a Smith number, since the sum of its digits (20) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 1490 + ... + 1590.

It is an arithmetic number, because the mean of its divisors is an integer number (8568).

2¹⁵⁵⁵⁴⁰ is an apocalyptic number.

155540 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 155540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (205632).

155540 is an abundant number, since it is smaller than the sum of its proper divisors (255724).

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

155540 is a wasteful number, since it uses less digits than its factorization.

155540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128 (or 126 counting only the distinct ones).

The product of its (nonzero) digits is 500, while the sum is 20.

The square root of 155540 is about 394.3855981143. The cubic root of 155540 is about 53.7791621092.

155540 divided by its sum of digits (20) gives a palindrome (7777).

It can be divided in two parts, 15 and 5540, that added together give a palindrome (5555).

The spelling of 155540 in words is "one hundred fifty-five thousand, five hundred forty".