9781121 has 4 divisors (see below), whose sum is σ = 11178432. Its totient is φ = 8383812.

The previous prime is 9781117. The next prime is 9781127. The reversal of 9781121 is 1211879.

9781121 is digitally balanced in base 2, base 3 and base 8, because in such bases it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1211879 = 17 ⋅71287.

It is a cyclic number.

It is not a de Polignac number, because 9781121 - 2² = 9781117 is a prime.

It is a Duffinian number.

9781121 is strictly pandigital in base 8.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (9781127) 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, 698645 + ... + 698658.

It is an arithmetic number, because the mean of its divisors is an integer number (2794608).

Almost surely, 2^9781121 is an apocalyptic number.

It is an amenable number.

9781121 is a deficient number, since it is larger than the sum of its proper divisors (1397311).

9781121 is a wasteful number, since it uses less digits than its factorization.

9781121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1397310.

The product of its digits is 1008, while the sum is 29.

The square root of 9781121 is about 3127.4783772234. The cubic root of 9781121 is about 213.8599908136.

It can be divided in two parts, 97 and 81121, that added together give a palindrome (81218).

The spelling of 9781121 in words is "nine million, seven hundred eighty-one thousand, one hundred twenty-one".