155489985 has 72 divisors (see below), whose sum is σ = 316270656. Its totient is φ = 70459200.

The previous prime is 155489963. The next prime is 155490001. The reversal of 155489985 is 589984551.

155489985 is a `hidden beast` number, since 1 + 5 + 548 + 9 + 98 + 5 = 666.

It is not a de Polignac number, because 155489985 - 2⁵ = 155489953 is a prime.

It is an unprimeable number.

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 71 ways as a sum of consecutive naturals, for example, 332722 + ... + 333188.

It is an arithmetic number, because the mean of its divisors is an integer number (4392648).

Almost surely, 2^155489985 is an apocalyptic number.

155489985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

155489985 is an abundant number, since it is smaller than the sum of its proper divisors (160780671).

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

155489985 is a wasteful number, since it uses less digits than its factorization.

155489985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643 (or 633 counting only the distinct ones).

The product of its digits is 2592000, while the sum is 54.

The square root of 155489985 is about 12469.5623419589. The cubic root of 155489985 is about 537.7339713313.

The spelling of 155489985 in words is "one hundred fifty-five million, four hundred eighty-nine thousand, nine hundred eighty-five".