155491 has 8 divisors (see below), whose sum is σ = 180320. Its totient is φ = 131328.

The previous prime is 155473. The next prime is 155501. The reversal of 155491 is 194551.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 155491 - 2¹¹ = 153443 is a prime.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (155461) 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 7 ways as a sum of consecutive naturals, for example, 565 + ... + 793.

It is an arithmetic number, because the mean of its divisors is an integer number (22540).

2¹⁵⁵⁴⁹¹ is an apocalyptic number.

155491 is a deficient number, since it is larger than the sum of its proper divisors (24829).

155491 is an equidigital number, since it uses as much as digits as its factorization.

155491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333.

The product of its digits is 900, while the sum is 25.

The square root of 155491 is about 394.3234712771. The cubic root of 155491 is about 53.7735141393.

Subtracting 155491 from its reverse (194551), we obtain a triangular number (39060 = T₂₇₉).

It can be divided in two parts, 155 and 491, that added together give a palindrome (646).

The spelling of 155491 in words is "one hundred fifty-five thousand, four hundred ninety-one".