989878767878989 has 2 divisors, whose sum is σ = 989878767878990. Its totient is φ = 989878767878988.

The previous prime is 989878767878971. The next prime is 989878767879061.

It is a happy number.

989878767878989 is nontrivially palindromic in base 10.

989878767878989 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 979689374000100 + 10189393878889 = 31299990^2 + 3192083^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 989878767878989 - 2²⁷ = 989878633661261 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (989878767875989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494939383939494 + 494939383939495.

It is an arithmetic number, because the mean of its divisors is an integer number (494939383939495).

Almost surely, 2^{989878767878989} is an apocalyptic number.

It is an amenable number.

989878767878989 is a deficient number, since it is larger than the sum of its proper divisors (1).

989878767878989 is an equidigital number, since it uses as much as digits as its factorization.

989878767878989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24777265250304, while the sum is 118.

It can be divided in two parts, 989878 and 767878989, that added together give a palindrome (768868867).

The spelling of 989878767878989 in words is "nine hundred eighty-nine trillion, eight hundred seventy-eight billion, seven hundred sixty-seven million, eight hundred seventy-eight thousand, nine hundred eighty-nine".