55221665 has 8 divisors (see below), whose sum is σ = 66513960. Its totient is φ = 44012032.

The previous prime is 55221641. The next prime is 55221671. The reversal of 55221665 is 56612255.

55221665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 1697809 + 53523856 = 1303^2 + 7316^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 55221665 - 2¹⁴ = 55205281 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19184 + ... + 21873.

It is an arithmetic number, because the mean of its divisors is an integer number (8314245).

Almost surely, 2^55221665 is an apocalyptic number.

It is an amenable number.

55221665 is a deficient number, since it is larger than the sum of its proper divisors (11292295).

55221665 is a wasteful number, since it uses less digits than its factorization.

55221665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41331.

The product of its digits is 18000, while the sum is 32.

The square root of 55221665 is about 7431.1281108591. The cubic root of 55221665 is about 380.8054591091.

The spelling of 55221665 in words is "fifty-five million, two hundred twenty-one thousand, six hundred sixty-five".