8987878989 has 10 divisors (see below), whose sum is σ = 13426337870. Its totient is φ = 5991919272.

The previous prime is 8987878973. The next prime is 8987879023. The reversal of 8987878989 is 9898787898.

8987878989 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It can be written as a sum of positive squares in only one way, i.e., 7839685764 + 1148193225 = 88542^2 + 33885^2 .

It is not a de Polignac number, because 8987878989 - 2⁴ = 8987878973 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (81), and also a Moran number because the ratio is a prime number: 110961469 = 8987878989 / (8 + 9 + 8 + 7 + 8 + 7 + 8 + 9 + 8 + 9).

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8987878589) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 55480654 + ... + 55480815.

It is an arithmetic number, because the mean of its divisors is an integer number (1342633787).

Almost surely, 2^8987878989 is an apocalyptic number.

It is an amenable number.

8987878989 is a deficient number, since it is larger than the sum of its proper divisors (4438458881).

8987878989 is a wasteful number, since it uses less digits than its factorization.

8987878989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110961481 (or 110961472 counting only the distinct ones).

The product of its digits is 1170505728, while the sum is 81.

The square root of 8987878989 is about 94804.4249441976. The cubic root of 8987878989 is about 2079.1495991249.

The spelling of 8987878989 in words is "eight billion, nine hundred eighty-seven million, eight hundred seventy-eight thousand, nine hundred eighty-nine".