33550221 has 4 divisors (see below), whose sum is σ = 44733632. Its totient is φ = 22366812.

The previous prime is 33550213. The next prime is 33550229. The reversal of 33550221 is 12205533.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12205533 = 3 ⋅4068511.

It is an interprime number because it is at equal distance from previous prime (33550213) and next prime (33550229).

It is not a de Polignac number, because 33550221 - 2³ = 33550213 is a prime.

It is a super-2 number, since 2×33550221² = 2251234658297682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33550229) 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, 5591701 + ... + 5591706.

It is an arithmetic number, because the mean of its divisors is an integer number (11183408).

Almost surely, 2^33550221 is an apocalyptic number.

It is an amenable number.

33550221 is a deficient number, since it is larger than the sum of its proper divisors (11183411).

33550221 is a wasteful number, since it uses less digits than its factorization.

33550221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11183410.

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

The square root of 33550221 is about 5792.2552602592. The cubic root of 33550221 is about 322.5262955543.

Adding to 33550221 its reverse (12205533), we get a palindrome (45755754).

The spelling of 33550221 in words is "thirty-three million, five hundred fifty thousand, two hundred twenty-one".