989159021 has 2 divisors, whose sum is σ = 989159022. Its totient is φ = 989159020.

The previous prime is 989159011. The next prime is 989159023. The reversal of 989159021 is 120951989.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 935503396 + 53655625 = 30586^2 + 7325^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-989159021 is a prime.

Together with 989159023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (989159023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494579510 + 494579511.

It is an arithmetic number, because the mean of its divisors is an integer number (494579511).

Almost surely, 2^989159021 is an apocalyptic number.

It is an amenable number.

989159021 is a deficient number, since it is larger than the sum of its proper divisors (1).

989159021 is an equidigital number, since it uses as much as digits as its factorization.

989159021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58320, while the sum is 44.

The square root of 989159021 is about 31450.8985722189. The cubic root of 989159021 is about 996.3732025757.

The spelling of 989159021 in words is "nine hundred eighty-nine million, one hundred fifty-nine thousand, twenty-one".