155987 has 8 divisors (see below), whose sum is σ = 171360. Its totient is φ = 141960.

The previous prime is 155921. The next prime is 156007. The reversal of 155987 is 789551.

It is not a de Polignac number, because 155987 - 2⁸ = 155731 is a prime.

It is a Duffinian number.

Its product of digits (12600) is a multiple of the sum of its prime divisors (84).

It is not an unprimeable number, because it can be changed into a prime (155087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2162 + ... + 2232.

It is an arithmetic number, because the mean of its divisors is an integer number (21420).

2¹⁵⁵⁹⁸⁷ is an apocalyptic number.

155987 is a deficient number, since it is larger than the sum of its proper divisors (15373).

155987 is an frugal number, since it uses more digits than its factorization.

155987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110 (or 84 counting only the distinct ones).

The product of its digits is 12600, while the sum is 35.

The square root of 155987 is about 394.9518958050. The cubic root of 155987 is about 53.8306307425.

Multiplying 155987 by its sum of digits (35), we get a palindrome (5459545).

The spelling of 155987 in words is "one hundred fifty-five thousand, nine hundred eighty-seven".