262640221 has 2 divisors, whose sum is σ = 262640222. Its totient is φ = 262640220.

The previous prime is 262640177. The next prime is 262640227. The reversal of 262640221 is 122046262.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 233631225 + 29008996 = 15285^2 + 5386^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-262640221 is a prime.

It is equal to p_14332372 and since 262640221 and 14332372 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (262640227) 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 as a sum of consecutive naturals, namely, 131320110 + 131320111.

It is an arithmetic number, because the mean of its divisors is an integer number (131320111).

Almost surely, 2^262640221 is an apocalyptic number.

It is an amenable number.

262640221 is a deficient number, since it is larger than the sum of its proper divisors (1).

262640221 is an equidigital number, since it uses as much as digits as its factorization.

262640221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 262640221 is about 16206.1784822950. The cubic root of 262640221 is about 640.4035711462.

Adding to 262640221 its reverse (122046262), we get a palindrome (384686483).

The spelling of 262640221 in words is "two hundred sixty-two million, six hundred forty thousand, two hundred twenty-one".