77455779840 has 576 divisors, whose sum is σ = 282217899600. Its totient is φ = 19619905536.

The previous prime is 77455779781. The next prime is 77455779847. The reversal of 77455779840 is 4897755477.

77455779840 is a `hidden beast` number, since 7 + 7 + 4 + 557 + 79 + 8 + 4 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 43517297664 + 33938482176 = 208608^2 + 184224^2 .

It is a tau number, because it is divible by the number of its divisors (576).

It is not an unprimeable number, because it can be changed into a prime (77455779847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 195102522 + ... + 195102918.

Almost surely, 2^77455779840 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 77455779840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141108949800).

77455779840 is an abundant number, since it is smaller than the sum of its proper divisors (204762119760).

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

77455779840 is a wasteful number, since it uses less digits than its factorization.

77455779840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 532 (or 509 counting only the distinct ones).

The product of its (nonzero) digits is 69148800, while the sum is 63.

The spelling of 77455779840 in words is "seventy-seven billion, four hundred fifty-five million, seven hundred seventy-nine thousand, eight hundred forty".