77718840 has 128 divisors (see below), whose sum is σ = 251942400. Its totient is φ = 19120640.

The previous prime is 77718827. The next prime is 77718841. The reversal of 77718840 is 4881777.

It is a junction number, because it is equal to n+sod(n) for n = 77718792 and 77718801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77718841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 79555 + ... + 80525.

It is an arithmetic number, because the mean of its divisors is an integer number (1968300).

Almost surely, 2^77718840 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 77718840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125971200).

77718840 is an abundant number, since it is smaller than the sum of its proper divisors (174223560).

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

77718840 is a wasteful number, since it uses less digits than its factorization.

77718840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1037 (or 1033 counting only the distinct ones).

The product of its (nonzero) digits is 87808, while the sum is 42.

The square root of 77718840 is about 8815.8289457090. The cubic root of 77718840 is about 426.7518737162.

The spelling of 77718840 in words is "seventy-seven million, seven hundred eighteen thousand, eight hundred forty".