10221391 has 2 divisors, whose sum is σ = 10221392. Its totient is φ = 10221390.

The previous prime is 10221377. The next prime is 10221397. The reversal of 10221391 is 19312201.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 10221391 - 2²¹ = 8124239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10221397) 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, 5110695 + 5110696.

It is an arithmetic number, because the mean of its divisors is an integer number (5110696).

Almost surely, 2^10221391 is an apocalyptic number.

10221391 is a deficient number, since it is larger than the sum of its proper divisors (1).

10221391 is an equidigital number, since it uses as much as digits as its factorization.

10221391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 10221391 is about 3197.0910215382. The cubic root of 10221391 is about 217.0217863407.

Adding to 10221391 its reverse (19312201), we get a palindrome (29533592).

The spelling of 10221391 in words is "ten million, two hundred twenty-one thousand, three hundred ninety-one".