989778859 has 4 divisors (see below), whose sum is σ = 1012797016. Its totient is φ = 966760704.

The previous prime is 989778847. The next prime is 989778871. The reversal of 989778859 is 958877989.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 958877989 = 2711 ⋅353699.

It is an interprime number because it is at equal distance from previous prime (989778847) and next prime (989778871).

It is a cyclic number.

It is not a de Polignac number, because 989778859 - 2⁹ = 989778347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (989778899) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11509014 + ... + 11509099.

It is an arithmetic number, because the mean of its divisors is an integer number (253199254).

Almost surely, 2^989778859 is an apocalyptic number.

989778859 is a deficient number, since it is larger than the sum of its proper divisors (23018157).

989778859 is a wasteful number, since it uses less digits than its factorization.

989778859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23018156.

The product of its digits is 91445760, while the sum is 70.

The square root of 989778859 is about 31460.7510876648. The cubic root of 989778859 is about 996.5812786634.

The spelling of 989778859 in words is "nine hundred eighty-nine million, seven hundred seventy-eight thousand, eight hundred fifty-nine".