989818997 has 2 divisors, whose sum is σ = 989818998. Its totient is φ = 989818996.

The previous prime is 989818957. The next prime is 989819009. The reversal of 989818997 is 799818989.

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., 954130321 + 35688676 = 30889^2 + 5974^2 .

It is a cyclic number.

It is not a de Polignac number, because 989818997 - 2¹² = 989814901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (989818957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494909498 + 494909499.

It is an arithmetic number, because the mean of its divisors is an integer number (494909499).

Almost surely, 2^989818997 is an apocalyptic number.

It is an amenable number.

989818997 is a deficient number, since it is larger than the sum of its proper divisors (1).

989818997 is an equidigital number, since it uses as much as digits as its factorization.

989818997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23514624, while the sum is 68.

The square root of 989818997 is about 31461.3889871379. The cubic root of 989818997 is about 996.5947497663.

The spelling of 989818997 in words is "nine hundred eighty-nine million, eight hundred eighteen thousand, nine hundred ninety-seven".