989388221 has 2 divisors, whose sum is σ = 989388222. Its totient is φ = 989388220.

The previous prime is 989388193. The next prime is 989388227. The reversal of 989388221 is 122883989.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 599760100 + 389628121 = 24490^2 + 19739^2 .

It is an emirp because it is prime and its reverse (122883989) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 989388221 - 2¹⁸ = 989126077 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 989388221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (989388227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494694110 + 494694111.

It is an arithmetic number, because the mean of its divisors is an integer number (494694111).

Almost surely, 2^989388221 is an apocalyptic number.

It is an amenable number.

989388221 is a deficient number, since it is larger than the sum of its proper divisors (1).

989388221 is an equidigital number, since it uses as much as digits as its factorization.

989388221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 497664, while the sum is 50.

The square root of 989388221 is about 31454.5421362321. The cubic root of 989388221 is about 996.4501538366.

The spelling of 989388221 in words is "nine hundred eighty-nine million, three hundred eighty-eight thousand, two hundred twenty-one".