989041021 has 2 divisors, whose sum is σ = 989041022. Its totient is φ = 989041020.

The previous prime is 989040989. The next prime is 989041049. The reversal of 989041021 is 120140989.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 562164100 + 426876921 = 23710^2 + 20661^2 .

It is a cyclic number.

It is not a de Polignac number, because 989041021 - 2⁵ = 989040989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (989041121) 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, 494520510 + 494520511.

It is an arithmetic number, because the mean of its divisors is an integer number (494520511).

Almost surely, 2^989041021 is an apocalyptic number.

It is an amenable number.

989041021 is a deficient number, since it is larger than the sum of its proper divisors (1).

989041021 is an equidigital number, since it uses as much as digits as its factorization.

989041021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 989041021 is about 31449.0225762264. The cubic root of 989041021 is about 996.3335807990. Note that the first 3 decimals are identical.

The spelling of 989041021 in words is "nine hundred eighty-nine million, forty-one thousand, twenty-one".