989775979 has 2 divisors, whose sum is σ = 989775980. Its totient is φ = 989775978.

The previous prime is 989775973. The next prime is 989776009. The reversal of 989775979 is 979577989.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 989775979 - 2³ = 989775971 is a prime.

It is not a weakly prime, because it can be changed into another prime (989775971) 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, 494887989 + 494887990.

It is an arithmetic number, because the mean of its divisors is an integer number (494887990).

Almost surely, 2^989775979 is an apocalyptic number.

989775979 is a deficient number, since it is larger than the sum of its proper divisors (1).

989775979 is an equidigital number, since it uses as much as digits as its factorization.

989775979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90016920, while the sum is 70.

The square root of 989775979 is about 31460.7053163148. The cubic root of 989775979 is about 996.5803120647.

The spelling of 989775979 in words is "nine hundred eighty-nine million, seven hundred seventy-five thousand, nine hundred seventy-nine".