65552221 has 8 divisors (see below), whose sum is σ = 79323840. Its totient is φ = 52882368.

The previous prime is 65552213. The next prime is 65552239. The reversal of 65552221 is 12225556.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 65552221 - 2³ = 65552213 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 65552221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65552251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 275311 + ... + 275548.

It is an arithmetic number, because the mean of its divisors is an integer number (9915480).

Almost surely, 2^65552221 is an apocalyptic number.

It is an amenable number.

65552221 is a deficient number, since it is larger than the sum of its proper divisors (13771619).

65552221 is a wasteful number, since it uses less digits than its factorization.

65552221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550883.

The product of its digits is 6000, while the sum is 28.

The square root of 65552221 is about 8096.4326094892. The cubic root of 65552221 is about 403.2079968606.

Adding to 65552221 its reverse (12225556), we get a palindrome (77777777).

The spelling of 65552221 in words is "sixty-five million, five hundred fifty-two thousand, two hundred twenty-one".