221236013 has 2 divisors, whose sum is σ = 221236014. Its totient is φ = 221236012.

The previous prime is 221236009. The next prime is 221236021. The reversal of 221236013 is 310632122.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 146361604 + 74874409 = 12098^2 + 8653^2 .

It is a cyclic number.

It is not a de Polignac number, because 221236013 - 2² = 221236009 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221230013) 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, 110618006 + 110618007.

It is an arithmetic number, because the mean of its divisors is an integer number (110618007).

Almost surely, 2^221236013 is an apocalyptic number.

It is an amenable number.

221236013 is a deficient number, since it is larger than the sum of its proper divisors (1).

221236013 is an equidigital number, since it uses as much as digits as its factorization.

221236013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 221236013 is about 14874.0046053509. The cubic root of 221236013 is about 604.8095049460.

Adding to 221236013 its reverse (310632122), we get a palindrome (531868135).

The spelling of 221236013 in words is "two hundred twenty-one million, two hundred thirty-six thousand, thirteen".