65222221 has 4 divisors (see below), whose sum is σ = 65820700. Its totient is φ = 64623744.

The previous prime is 65222207. The next prime is 65222243. The reversal of 65222221 is 12222256.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 38812900 + 26409321 = 6230^2 + 5139^2 .

It is a cyclic number.

It is not a de Polignac number, because 65222221 - 2¹¹ = 65220173 is a prime.

It is a super-2 number, since 2×65222221² = 8507876224345682, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 65222192 and 65222201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65222281) 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, 299076 + ... + 299293.

It is an arithmetic number, because the mean of its divisors is an integer number (16455175).

Almost surely, 2^65222221 is an apocalyptic number.

It is an amenable number.

65222221 is a deficient number, since it is larger than the sum of its proper divisors (598479).

65222221 is a wasteful number, since it uses less digits than its factorization.

65222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 598478.

The product of its digits is 960, while the sum is 22.

The square root of 65222221 is about 8076.0275507207. The cubic root of 65222221 is about 402.5302545318.

Adding to 65222221 its reverse (12222256), we get a palindrome (77444477).

The spelling of 65222221 in words is "sixty-five million, two hundred twenty-two thousand, two hundred twenty-one".