989878742821 has 8 divisors (see below), whose sum is σ = 1002171582720. Its totient is φ = 977628513408.

The previous prime is 989878742803. The next prime is 989878742873. The reversal of 989878742821 is 128247878989.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 989878742821 - 2¹⁷ = 989878611749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (989878742521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10605871 + ... + 10698796.

It is an arithmetic number, because the mean of its divisors is an integer number (125271447840).

Almost surely, 2^989878742821 is an apocalyptic number.

It is an amenable number.

989878742821 is a deficient number, since it is larger than the sum of its proper divisors (12292839899).

989878742821 is a wasteful number, since it uses less digits than its factorization.

989878742821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21305243.

The product of its digits is 260112384, while the sum is 73.

The spelling of 989878742821 in words is "nine hundred eighty-nine billion, eight hundred seventy-eight million, seven hundred forty-two thousand, eight hundred twenty-one".