55218505 has 8 divisors (see below), whose sum is σ = 66325824. Its totient is φ = 44132400.

The previous prime is 55218497. The next prime is 55218517. The reversal of 55218505 is 50581255.

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

It is not a de Polignac number, because 55218505 - 2³ = 55218497 is a prime.

It is a Duffinian number.

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 7 ways as a sum of consecutive naturals, for example, 1140 + ... + 10570.

It is an arithmetic number, because the mean of its divisors is an integer number (8290728).

Almost surely, 2^55218505 is an apocalyptic number.

It is an amenable number.

55218505 is a deficient number, since it is larger than the sum of its proper divisors (11107319).

55218505 is a wasteful number, since it uses less digits than its factorization.

55218505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10607.

The product of its (nonzero) digits is 10000, while the sum is 31.

The square root of 55218505 is about 7430.9154886864. The cubic root of 55218505 is about 380.7981952438.

The spelling of 55218505 in words is "fifty-five million, two hundred eighteen thousand, five hundred five".