77785449984 has 640 divisors, whose sum is σ = 268697088000. Its totient is φ = 21985689600.

The previous prime is 77785449967. The next prime is 77785449997. The reversal of 77785449984 is 48994458777.

77785449984 is a `hidden beast` number, since 7 + 7 + 7 + 8 + 54 + 499 + 84 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 136705252 + ... + 136705820.

It is an arithmetic number, because the mean of its divisors is an integer number (419839200).

Almost surely, 2^77785449984 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 77785449984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134348544000).

77785449984 is an abundant number, since it is smaller than the sum of its proper divisors (190911638016).

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

77785449984 is a wasteful number, since it uses less digits than its factorization.

77785449984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667 (or 645 counting only the distinct ones).

The product of its digits is 568995840, while the sum is 72.

The spelling of 77785449984 in words is "seventy-seven billion, seven hundred eighty-five million, four hundred forty-nine thousand, nine hundred eighty-four".