155605 has 4 divisors (see below), whose sum is σ = 186732. Its totient is φ = 124480.

The previous prime is 155599. The next prime is 155609. The reversal of 155605 is 506551.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 69169 + 86436 = 263^2 + 294^2 .

It is not a de Polignac number, because 155605 - 2¹¹ = 153557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155609) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15556 + ... + 15565.

It is an arithmetic number, because the mean of its divisors is an integer number (46683).

2¹⁵⁵⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

155605 is a deficient number, since it is larger than the sum of its proper divisors (31127).

155605 is an equidigital number, since it uses as much as digits as its factorization.

155605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31126.

The product of its (nonzero) digits is 750, while the sum is 22.

The square root of 155605 is about 394.4679961670. The cubic root of 155605 is about 53.7866524841.

The spelling of 155605 in words is "one hundred fifty-five thousand, six hundred five".