778988 has 24 divisors (see below), whose sum is σ = 1596672. Its totient is φ = 325584.

The previous prime is 778979. The next prime is 778993. The reversal of 778988 is 889877.

It is an unprimeable number.

778988 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 881 + ... + 1527.

It is an arithmetic number, because the mean of its divisors is an integer number (66528).

2⁷⁷⁸⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 778988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (798336).

778988 is an abundant number, since it is smaller than the sum of its proper divisors (817684).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

778988 is a wasteful number, since it uses less digits than its factorization.

778988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 701 (or 699 counting only the distinct ones).

The product of its digits is 225792, while the sum is 47.

The square root of 778988 is about 882.6029684972. The cubic root of 778988 is about 92.0118132279.

Subtracting 778988 from its reverse (889877), we obtain a square (110889 = 333²).

It can be divided in two parts, 77 and 8988, that multiplied together give a triangular number (692076 = T₁₁₇₆).

The spelling of 778988 in words is "seven hundred seventy-eight thousand, nine hundred eighty-eight".