9778 has 4 divisors (see below), whose sum is σ = 14670. Its totient is φ = 4888.

The previous prime is 9769. The next prime is 9781. The reversal of 9778 is 8779.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 7569 + 2209 = 87^2 + 47^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a plaindrome in base 12.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2443 + ... + 2446.

2⁹⁷⁷⁸ is an apocalyptic number.

9778 is a deficient number, since it is larger than the sum of its proper divisors (4892).

9778 is a wasteful number, since it uses less digits than its factorization.

9778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4891.

The product of its digits is 3528, while the sum is 31.

The square root of 9778 is about 98.8837701547. The cubic root of 9778 is about 21.3837241954.

Subtracting from 9778 its reverse (8779), we obtain a palindrome (999).

It can be divided in two parts, 9 and 778, that added together give a palindrome (787).

The spelling of 9778 in words is "nine thousand, seven hundred seventy-eight".