33551553221 has 2 divisors, whose sum is σ = 33551553222. Its totient is φ = 33551553220.

The previous prime is 33551553143. The next prime is 33551553253. The reversal of 33551553221 is 12235515533.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16896360196 + 16655193025 = 129986^2 + 129055^2 .

It is a cyclic number.

It is not a de Polignac number, because 33551553221 - 2¹⁸ = 33551291077 is a prime.

It is a super-2 number, since 2×33551553221² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (33551553281) 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 as a sum of consecutive naturals, namely, 16775776610 + 16775776611.

It is an arithmetic number, because the mean of its divisors is an integer number (16775776611).

Almost surely, 2^33551553221 is an apocalyptic number.

It is an amenable number.

33551553221 is a deficient number, since it is larger than the sum of its proper divisors (1).

33551553221 is an equidigital number, since it uses as much as digits as its factorization.

33551553221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 67500, while the sum is 35.

The spelling of 33551553221 in words is "thirty-three billion, five hundred fifty-one million, five hundred fifty-three thousand, two hundred twenty-one".