77788816 has 40 divisors (see below), whose sum is σ = 173344064. Its totient is φ = 33125760.

The previous prime is 77788813. The next prime is 77788819. The reversal of 77788816 is 61888777.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (77788813) and next prime (77788819).

It is not an unprimeable number, because it can be changed into a prime (77788811) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16126 + ... + 20386.

Almost surely, 2^77788816 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 77788816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86672032).

77788816 is an abundant number, since it is smaller than the sum of its proper divisors (95555248).

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

77788816 is a wasteful number, since it uses less digits than its factorization.

77788816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4439 (or 4433 counting only the distinct ones).

The product of its digits is 1053696, while the sum is 52.

The square root of 77788816 is about 8819.7968230566. The cubic root of 77788816 is about 426.8799140179.

The spelling of 77788816 in words is "seventy-seven million, seven hundred eighty-eight thousand, eight hundred sixteen".