52640221 has 2 divisors, whose sum is σ = 52640222. Its totient is φ = 52640220.

The previous prime is 52640219. The next prime is 52640293. The reversal of 52640221 is 12204625.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42432196 + 10208025 = 6514^2 + 3195^2 .

It is a cyclic number.

It is not a de Polignac number, because 52640221 - 2¹ = 52640219 is a prime.

Together with 52640219, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 52640192 and 52640201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (52646221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26320110 + 26320111.

It is an arithmetic number, because the mean of its divisors is an integer number (26320111).

Almost surely, 2^52640221 is an apocalyptic number.

It is an amenable number.

52640221 is a deficient number, since it is larger than the sum of its proper divisors (1).

52640221 is an equidigital number, since it uses as much as digits as its factorization.

52640221 is an odious number, because the sum of its binary digits is odd.

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

The square root of 52640221 is about 7255.3580890263. The cubic root of 52640221 is about 374.7766871916.

Adding to 52640221 its reverse (12204625), we get a palindrome (64844846).

The spelling of 52640221 in words is "fifty-two million, six hundred forty thousand, two hundred twenty-one".