55181985 has 32 divisors (see below), whose sum is σ = 95468160. Its totient is φ = 27122688.

The previous prime is 55181939. The next prime is 55181999. The reversal of 55181985 is 58918155.

It is not a de Polignac number, because 55181985 - 2⁶ = 55181921 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7929 + ... + 13161.

It is an arithmetic number, because the mean of its divisors is an integer number (2983380).

Almost surely, 2^55181985 is an apocalyptic number.

It is an amenable number.

55181985 is a deficient number, since it is larger than the sum of its proper divisors (40286175).

55181985 is a wasteful number, since it uses less digits than its factorization.

55181985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5297.

The product of its digits is 72000, while the sum is 42.

The square root of 55181985 is about 7428.4577807241. The cubic root of 55181985 is about 380.7142269131.

It can be divided in two parts, 5518 and 1985, that added together give a triangular number (7503 = T₁₂₂).

The spelling of 55181985 in words is "fifty-five million, one hundred eighty-one thousand, nine hundred eighty-five".