989873987 has 4 divisors (see below), whose sum is σ = 1016627376. Its totient is φ = 963120600.

The previous prime is 989873933. The next prime is 989873993. The reversal of 989873987 is 789378989.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 789378989 = 7 ⋅112768427.

It is a cyclic number.

It is not a de Polignac number, because 989873987 - 2¹² = 989869891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (989873917) 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, 13376639 + ... + 13376712.

It is an arithmetic number, because the mean of its divisors is an integer number (254156844).

Almost surely, 2^989873987 is an apocalyptic number.

989873987 is a deficient number, since it is larger than the sum of its proper divisors (26753389).

989873987 is a wasteful number, since it uses less digits than its factorization.

989873987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26753388.

The product of its digits is 54867456, while the sum is 68.

The square root of 989873987 is about 31462.2629033577. The cubic root of 989873987 is about 996.6132049016.

The spelling of 989873987 in words is "nine hundred eighty-nine million, eight hundred seventy-three thousand, nine hundred eighty-seven".