989898251027921 has 2 divisors, whose sum is σ = 989898251027922. Its totient is φ = 989898251027920.

The previous prime is 989898251027839. The next prime is 989898251027951. The reversal of 989898251027921 is 129720152898989.

989898251027921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 988385569960000 + 1512681067921 = 31438600^2 + 1229911^2 .

It is a cyclic number.

It is not a de Polignac number, because 989898251027921 - 2¹⁸ = 989898250765777 is a prime.

It is not a weakly prime, because it can be changed into another prime (989898251027951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494949125513960 + 494949125513961.

It is an arithmetic number, because the mean of its divisors is an integer number (494949125513961).

Almost surely, 2^{989898251027921} is an apocalyptic number.

It is an amenable number.

989898251027921 is a deficient number, since it is larger than the sum of its proper divisors (1).

989898251027921 is an equidigital number, since it uses as much as digits as its factorization.

989898251027921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 940584960, while the sum is 80.

The spelling of 989898251027921 in words is "nine hundred eighty-nine trillion, eight hundred ninety-eight billion, two hundred fifty-one million, twenty-seven thousand, nine hundred twenty-one".