77665744512 has 320 divisors, whose sum is σ = 238836213000. Its totient is φ = 25034489856.

The previous prime is 77665744489. The next prime is 77665744517. The reversal of 77665744512 is 21544756677.

77665744512 is a `hidden beast` number, since 7 + 7 + 66 + 574 + 4 + 5 + 1 + 2 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 77359634496 + 306110016 = 278136^2 + 17496^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (77665744517) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 74037364 + ... + 74038412.

Almost surely, 2^77665744512 is an apocalyptic number.

77665744512 is a gapful number since it is divisible by the number (72) 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 77665744512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119418106500).

77665744512 is an abundant number, since it is smaller than the sum of its proper divisors (161170468488).

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

77665744512 is a wasteful number, since it uses less digits than its factorization.

77665744512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1305 (or 1284 counting only the distinct ones).

The product of its digits is 9878400, while the sum is 54.

The spelling of 77665744512 in words is "seventy-seven billion, six hundred sixty-five million, seven hundred forty-four thousand, five hundred twelve".