155490 has 32 divisors (see below), whose sum is σ = 383616. Its totient is φ = 40320.

The previous prime is 155473. The next prime is 155501. The reversal of 155490 is 94551.

It is an Ulam number.

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 155490.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2094 + ... + 2166.

It is an arithmetic number, because the mean of its divisors is an integer number (11988).

2¹⁵⁵⁴⁹⁰ is an apocalyptic number.

155490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 155490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (191808).

155490 is an abundant number, since it is smaller than the sum of its proper divisors (228126).

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

155490 is a wasteful number, since it uses less digits than its factorization.

155490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154.

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 155490 is about 394.3222032805. The cubic root of 155490 is about 53.7733988623.

The spelling of 155490 in words is "one hundred fifty-five thousand, four hundred ninety".