155805 has 32 divisors (see below), whose sum is σ = 290304. Its totient is φ = 70656.

The previous prime is 155801. The next prime is 155809. The reversal of 155805 is 508551.

It is an interprime number because it is at equal distance from previous prime (155801) and next prime (155809).

It is not a de Polignac number, because 155805 - 2² = 155801 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155801) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3292 + ... + 3338.

It is an arithmetic number, because the mean of its divisors is an integer number (9072).

2¹⁵⁵⁸⁰⁵ is an apocalyptic number.

155805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

155805 is a deficient number, since it is larger than the sum of its proper divisors (134499).

155805 is a wasteful number, since it uses less digits than its factorization.

155805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85.

The product of its (nonzero) digits is 1000, while the sum is 24.

The square root of 155805 is about 394.7214207514. The cubic root of 155805 is about 53.8096867160.

The spelling of 155805 in words is "one hundred fifty-five thousand, eight hundred five".