33521421 has 4 divisors (see below), whose sum is σ = 44695232. Its totient is φ = 22347612.

The previous prime is 33521417. The next prime is 33521431. The reversal of 33521421 is 12412533.

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 33521421 - 2² = 33521417 is a prime.

It is a super-2 number, since 2×33521421² = 2247371331718482, 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 (33521401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5586901 + ... + 5586906.

It is an arithmetic number, because the mean of its divisors is an integer number (11173808).

Almost surely, 2^33521421 is an apocalyptic number.

It is an amenable number.

33521421 is a deficient number, since it is larger than the sum of its proper divisors (11173811).

33521421 is a wasteful number, since it uses less digits than its factorization.

33521421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11173810.

The product of its digits is 720, while the sum is 21.

The square root of 33521421 is about 5789.7686482277. The cubic root of 33521421 is about 322.4339820397.

Adding to 33521421 its reverse (12412533), we get a palindrome (45933954).

The spelling of 33521421 in words is "thirty-three million, five hundred twenty-one thousand, four hundred twenty-one".