77991760 has 120 divisors (see below), whose sum is σ = 227985408. Its totient is φ = 24288000.

The previous prime is 77991743. The next prime is 77991761. The reversal of 77991760 is 6719977.

It is a self number, because there is not a number n which added to its sum of digits gives 77991760.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77991761) 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, 67185 + ... + 68335.

Almost surely, 2^77991760 is an apocalyptic number.

77991760 is a gapful number since it is divisible by the number (70) 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 77991760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113992704).

77991760 is an abundant number, since it is smaller than the sum of its proper divisors (149993648).

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

77991760 is a wasteful number, since it uses less digits than its factorization.

77991760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1193 (or 1176 counting only the distinct ones).

The product of its (nonzero) digits is 166698, while the sum is 46.

The square root of 77991760 is about 8831.2943558688. The cubic root of 77991760 is about 427.2508220384.

It can be divided in two parts, 779917 and 60, that added together give a palindrome (779977).

The spelling of 77991760 in words is "seventy-seven million, nine hundred ninety-one thousand, seven hundred sixty".