989878979 has 2 divisors, whose sum is σ = 989878980. Its totient is φ = 989878978.

The previous prime is 989878969. The next prime is 989878997. The reversal of 989878979 is 979878989.

Together with next prime (989878997) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is an emirp because it is prime and its reverse (979878989) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 989878979 - 2¹² = 989874883 is a prime.

It is not a weakly prime, because it can be changed into another prime (989878969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494939489 + 494939490.

It is an arithmetic number, because the mean of its divisors is an integer number (494939490).

Almost surely, 2^989878979 is an apocalyptic number.

989878979 is a deficient number, since it is larger than the sum of its proper divisors (1).

989878979 is an equidigital number, since it uses as much as digits as its factorization.

989878979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 164602368, while the sum is 74.

The square root of 989878979 is about 31462.3422363943. The cubic root of 989878979 is about 996.6148802275.

The spelling of 989878979 in words is "nine hundred eighty-nine million, eight hundred seventy-eight thousand, nine hundred seventy-nine".