77778144 has 120 divisors (see below), whose sum is σ = 235215288. Its totient is φ = 25194240.

The previous prime is 77778139. The next prime is 77778167. The reversal of 77778144 is 44187777.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 77778144.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 95499 + ... + 96309.

Almost surely, 2^77778144 is an apocalyptic number.

77778144 is a gapful number since it is divisible by the number (74) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77778144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117607644).

77778144 is an abundant number, since it is smaller than the sum of its proper divisors (157437144).

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

77778144 is a wasteful number, since it uses less digits than its factorization.

77778144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870 (or 853 counting only the distinct ones).

The product of its digits is 307328, while the sum is 45.

The square root of 77778144 is about 8819.1917997059. The cubic root of 77778144 is about 426.8603916279.

The spelling of 77778144 in words is "seventy-seven million, seven hundred seventy-eight thousand, one hundred forty-four".