9781138 has 8 divisors (see below), whose sum is σ = 14920560. Its totient is φ = 4807620.

The previous prime is 9781127. The next prime is 9781139. The reversal of 9781138 is 8311879.

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

It is a junction number, because it is equal to n+sod(n) for n = 9781097 and 9781106.

It is not an unprimeable number, because it can be changed into a prime (9781139) 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, 41328 + ... + 41563.

It is an arithmetic number, because the mean of its divisors is an integer number (1865070).

Almost surely, 2^9781138 is an apocalyptic number.

9781138 is a deficient number, since it is larger than the sum of its proper divisors (5139422).

9781138 is a wasteful number, since it uses less digits than its factorization.

9781138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82952.

The product of its digits is 12096, while the sum is 37.

The square root of 9781138 is about 3127.4810950668. The cubic root of 9781138 is about 213.8601147127.

It can be divided in two parts, 978113 and 8, that added together give a square (978121 = 989²).

The spelling of 9781138 in words is "nine million, seven hundred eighty-one thousand, one hundred thirty-eight".