55033221 has 4 divisors (see below), whose sum is σ = 73377632. Its totient is φ = 36688812.

The previous prime is 55033211. The next prime is 55033243. The reversal of 55033221 is 12233055.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 55033221 - 2⁷ = 55033093 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55033211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9172201 + ... + 9172206.

It is an arithmetic number, because the mean of its divisors is an integer number (18344408).

Almost surely, 2^55033221 is an apocalyptic number.

It is an amenable number.

55033221 is a deficient number, since it is larger than the sum of its proper divisors (18344411).

55033221 is a wasteful number, since it uses less digits than its factorization.

55033221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18344410.

The product of its (nonzero) digits is 900, while the sum is 21.

The square root of 55033221 is about 7418.4379083470. The cubic root of 55033221 is about 380.3717990794.

Adding to 55033221 its reverse (12233055), we get a palindrome (67266276).

The spelling of 55033221 in words is "fifty-five million, thirty-three thousand, two hundred twenty-one".