913788221 has 2 divisors, whose sum is σ = 913788222. Its totient is φ = 913788220.

The previous prime is 913788203. The next prime is 913788257. The reversal of 913788221 is 122887319.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 908359321 + 5428900 = 30139^2 + 2330^2 .

It is an emirp because it is prime and its reverse (122887319) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 913788221 - 2²⁶ = 846679357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (913781221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 456894110 + 456894111.

It is an arithmetic number, because the mean of its divisors is an integer number (456894111).

Almost surely, 2^913788221 is an apocalyptic number.

It is an amenable number.

913788221 is a deficient number, since it is larger than the sum of its proper divisors (1).

913788221 is an equidigital number, since it uses as much as digits as its factorization.

913788221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 41.

The square root of 913788221 is about 30228.9301993967. The cubic root of 913788221 is about 970.3949293471.

It can be divided in two parts, 91378 and 8221, that added together give a palindrome (99599).

The spelling of 913788221 in words is "nine hundred thirteen million, seven hundred eighty-eight thousand, two hundred twenty-one".