977778 has 32 divisors (see below), whose sum is σ = 2289600. Its totient is φ = 308448.

The previous prime is 977761. The next prime is 977791. The reversal of 977778 is 877779.

It is a nialpdrome in base 16.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 550 + ... + 1502.

It is an arithmetic number, because the mean of its divisors is an integer number (71550).

2⁹⁷⁷⁷⁷⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 977778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1144800).

977778 is an abundant number, since it is smaller than the sum of its proper divisors (1311822).

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

977778 is a wasteful number, since it uses less digits than its factorization.

With its successor (977779) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (977).

977778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 983 (or 977 counting only the distinct ones).

The product of its digits is 172872, while the sum is 45.

The square root of 977778 is about 988.8265773127. The cubic root of 977778 is about 99.2537110495.

Subtracting from 977778 its reverse (877779), we obtain a palindrome (99999).

It can be divided in two parts, 97 and 7778, that added together give a triangular number (7875 = T₁₂₅).

The spelling of 977778 in words is "nine hundred seventy-seven thousand, seven hundred seventy-eight".