9781988 has 12 divisors (see below), whose sum is σ = 17670912. Its totient is φ = 4733160.

The previous prime is 9781963. The next prime is 9781991. The reversal of 9781988 is 8891879.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39320 + ... + 39567.

It is an arithmetic number, because the mean of its divisors is an integer number (1472576).

Almost surely, 2^9781988 is an apocalyptic number.

It is an amenable number.

9781988 is a deficient number, since it is larger than the sum of its proper divisors (7888924).

9781988 is a wasteful number, since it uses less digits than its factorization.

9781988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78922 (or 78920 counting only the distinct ones).

The product of its digits is 290304, while the sum is 50.

The square root of 9781988 is about 3127.6169842230. The cubic root of 9781988 is about 213.8663094872.

The spelling of 9781988 in words is "nine million, seven hundred eighty-one thousand, nine hundred eighty-eight".