33636221 has 4 divisors (see below), whose sum is σ = 33667452. Its totient is φ = 33604992.

The previous prime is 33636203. The next prime is 33636223. The reversal of 33636221 is 12263633.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12263633 = 41 ⋅299113.

It can be written as a sum of positive squares in 2 ways, for example, as 15912121 + 17724100 = 3989^2 + 4210^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-33636221 is a prime.

It is a super-2 number, since 2×33636221² = 2262790726321682, 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 (33636223) 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, 13940 + ... + 16173.

It is an arithmetic number, because the mean of its divisors is an integer number (8416863).

Almost surely, 2^33636221 is an apocalyptic number.

It is an amenable number.

33636221 is a deficient number, since it is larger than the sum of its proper divisors (31231).

33636221 is a wasteful number, since it uses less digits than its factorization.

33636221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31230.

The product of its digits is 3888, while the sum is 26.

The square root of 33636221 is about 5799.6742149883. The cubic root of 33636221 is about 322.8016399430.

Adding to 33636221 its reverse (12263633), we get a palindrome (45899854).

The spelling of 33636221 in words is "thirty-three million, six hundred thirty-six thousand, two hundred twenty-one".