989556641 has 2 divisors, whose sum is σ = 989556642. Its totient is φ = 989556640.

The previous prime is 989556637. The next prime is 989556649. The reversal of 989556641 is 146655989.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 944947600 + 44609041 = 30740^2 + 6679^2 .

It is an emirp because it is prime and its reverse (146655989) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 989556641 - 2² = 989556637 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (989556649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494778320 + 494778321.

It is an arithmetic number, because the mean of its divisors is an integer number (494778321).

Almost surely, 2^989556641 is an apocalyptic number.

It is an amenable number.

989556641 is a deficient number, since it is larger than the sum of its proper divisors (1).

989556641 is an equidigital number, since it uses as much as digits as its factorization.

989556641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2332800, while the sum is 53.

The square root of 989556641 is about 31457.2192191236. The cubic root of 989556641 is about 996.5066913378.

The spelling of 989556641 in words is "nine hundred eighty-nine million, five hundred fifty-six thousand, six hundred forty-one".