77688840 has 64 divisors (see below), whose sum is σ = 237038400. Its totient is φ = 20364032.

The previous prime is 77688803. The next prime is 77688841. The reversal of 77688840 is 4888677.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 77688840.

It is not an unprimeable number, because it can be changed into a prime (77688841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1594 + ... + 12566.

It is an arithmetic number, because the mean of its divisors is an integer number (3703725).

Almost surely, 2^77688840 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 77688840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118519200).

77688840 is an abundant number, since it is smaller than the sum of its proper divisors (159349560).

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

77688840 is a wasteful number, since it uses less digits than its factorization.

77688840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11046 (or 11042 counting only the distinct ones).

The product of its (nonzero) digits is 602112, while the sum is 48.

The square root of 77688840 is about 8814.1272965620. The cubic root of 77688840 is about 426.6969569424.

The spelling of 77688840 in words is "seventy-seven million, six hundred eighty-eight thousand, eight hundred forty".