55221685 has 4 divisors (see below), whose sum is σ = 66266028. Its totient is φ = 44177344.

The previous prime is 55221671. The next prime is 55221697. The reversal of 55221685 is 58612255.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30041361 + 25180324 = 5481^2 + 5018^2 .

It is a cyclic number.

It is not a de Polignac number, because 55221685 - 2⁷ = 55221557 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 55221685.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5522164 + ... + 5522173.

It is an arithmetic number, because the mean of its divisors is an integer number (16566507).

Almost surely, 2^55221685 is an apocalyptic number.

It is an amenable number.

55221685 is a deficient number, since it is larger than the sum of its proper divisors (11044343).

55221685 is a wasteful number, since it uses less digits than its factorization.

55221685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11044342.

The product of its digits is 24000, while the sum is 34.

The square root of 55221685 is about 7431.1294565497. The cubic root of 55221685 is about 380.8055050820.

The spelling of 55221685 in words is "fifty-five million, two hundred twenty-one thousand, six hundred eighty-five".