155903 has 4 divisors (see below), whose sum is σ = 170088. Its totient is φ = 141720.

The previous prime is 155893. The next prime is 155921. The reversal of 155903 is 309551.

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

It is a cyclic number.

It is not a de Polignac number, because 155903 - 2⁴ = 155887 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7076 + ... + 7097.

It is an arithmetic number, because the mean of its divisors is an integer number (42522).

2¹⁵⁵⁹⁰³ is an apocalyptic number.

155903 is a deficient number, since it is larger than the sum of its proper divisors (14185).

155903 is a wasteful number, since it uses less digits than its factorization.

155903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14184.

The product of its (nonzero) digits is 675, while the sum is 23.

The square root of 155903 is about 394.8455394202. The cubic root of 155903 is about 53.8209662942.

The spelling of 155903 in words is "one hundred fifty-five thousand, nine hundred three".