55320221 has 8 divisors (see below), whose sum is σ = 62973504. Its totient is φ = 48104320.

The previous prime is 55320211. The next prime is 55320233. The reversal of 55320221 is 12202355.

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

It is not a de Polignac number, because 55320221 - 2⁶ = 55320157 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 55320193 and 55320202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55320211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109076 + ... + 109581.

It is an arithmetic number, because the mean of its divisors is an integer number (7871688).

Almost surely, 2^55320221 is an apocalyptic number.

It is an amenable number.

55320221 is a deficient number, since it is larger than the sum of its proper divisors (7653283).

55320221 is a wasteful number, since it uses less digits than its factorization.

55320221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218691.

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 55320221 is about 7437.7564493603. The cubic root of 55320221 is about 381.0318699904.

Adding to 55320221 its reverse (12202355), we get a palindrome (67522576).

The spelling of 55320221 in words is "fifty-five million, three hundred twenty thousand, two hundred twenty-one".