155559 has 4 divisors (see below), whose sum is σ = 207416. Its totient is φ = 103704.

The previous prime is 155557. The next prime is 155569. The reversal of 155559 is 955551.

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

It is not a de Polignac number, because 155559 - 2¹ = 155557 is a prime.

It is a D-number.

It is a Duffinian number.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155557) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25924 + ... + 25929.

It is an arithmetic number, because the mean of its divisors is an integer number (51854).

2¹⁵⁵⁵⁵⁹ is an apocalyptic number.

155559 is a deficient number, since it is larger than the sum of its proper divisors (51857).

155559 is an equidigital number, since it uses as much as digits as its factorization.

155559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51856.

The product of its digits is 5625, while the sum is 30.

The square root of 155559 is about 394.4096854795. The cubic root of 155559 is about 53.7813518192.

The spelling of 155559 in words is "one hundred fifty-five thousand, five hundred fifty-nine".