989878697 has 4 divisors (see below), whose sum is σ = 991594836. Its totient is φ = 988162560.

The previous prime is 989878693. The next prime is 989878699. The reversal of 989878697 is 796878989.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 513067801 + 476810896 = 22651^2 + 21836^2 .

It is a cyclic number.

It is not a de Polignac number, because 989878697 - 2² = 989878693 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 989878697.

It is not an unprimeable number, because it can be changed into a prime (989878693) 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 in 3 ways as a sum of consecutive naturals, for example, 857204 + ... + 858357.

It is an arithmetic number, because the mean of its divisors is an integer number (247898709).

Almost surely, 2^989878697 is an apocalyptic number.

It is an amenable number.

989878697 is a deficient number, since it is larger than the sum of its proper divisors (1716139).

989878697 is a wasteful number, since it uses less digits than its factorization.

989878697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1716138.

The product of its digits is 109734912, while the sum is 71.

The square root of 989878697 is about 31462.3377548459. The cubic root of 989878697 is about 996.6147855879.

The spelling of 989878697 in words is "nine hundred eighty-nine million, eight hundred seventy-eight thousand, six hundred ninety-seven".