77878224 has 120 divisors (see below), whose sum is σ = 238946760. Its totient is φ = 23568384.

The previous prime is 77878223. The next prime is 77878243. The reversal of 77878224 is 42287877.

It can be written as a sum of positive squares in 4 ways, for example, as 14197824 + 63680400 = 3768^2 + 7980^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 77878224.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77878223) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 70444 + ... + 71540.

It is an arithmetic number, because the mean of its divisors is an integer number (1991223).

Almost surely, 2^77878224 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 77878224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119473380).

77878224 is an abundant number, since it is smaller than the sum of its proper divisors (161068536).

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

77878224 is a wasteful number, since it uses less digits than its factorization.

77878224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1157 (or 1148 counting only the distinct ones).

The product of its digits is 351232, while the sum is 45.

The square root of 77878224 is about 8824.8639649572. The cubic root of 77878224 is about 427.0433988142.

The spelling of 77878224 in words is "seventy-seven million, eight hundred seventy-eight thousand, two hundred twenty-four".