155988 has 36 divisors (see below), whose sum is σ = 451360. Its totient is φ = 44496.

The previous prime is 155921. The next prime is 156007. The reversal of 155988 is 889551.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×155988² = 48664512288, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nialpdrome in base 12.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58 + ... + 561.

2¹⁵⁵⁹⁸⁸ is an apocalyptic number.

155988 is a gapful number since it is divisible by the number (18) 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 155988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (225680).

155988 is an abundant number, since it is smaller than the sum of its proper divisors (295372).

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

155988 is a wasteful number, since it uses less digits than its factorization.

155988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636 (or 631 counting only the distinct ones).

The product of its digits is 14400, while the sum is 36.

The square root of 155988 is about 394.9531617800. The cubic root of 155988 is about 53.8307457746.

The spelling of 155988 in words is "one hundred fifty-five thousand, nine hundred eighty-eight".