978778 has 4 divisors (see below), whose sum is σ = 1468170. Its totient is φ = 489388.

The previous prime is 978773. The next prime is 978797. The reversal of 978778 is 877879.

It is a happy number.

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., 683929 + 294849 = 827^2 + 543^2 .

It is not an unprimeable number, because it can be changed into a prime (978773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 244693 + ... + 244696.

2⁹⁷⁸⁷⁷⁸ is an apocalyptic number.

978778 is a deficient number, since it is larger than the sum of its proper divisors (489392).

978778 is a wasteful number, since it uses less digits than its factorization.

978778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 489391.

The product of its digits is 197568, while the sum is 46.

The square root of 978778 is about 989.3320979327. The cubic root of 978778 is about 99.2875360056.

It can be divided in two parts, 9 and 78778, that added together give a palindrome (78787).

The spelling of 978778 in words is "nine hundred seventy-eight thousand, seven hundred seventy-eight".