77531779782 has 12 divisors (see below), whose sum is σ = 167985522900. Its totient is φ = 25843926588.

The previous prime is 77531779771. The next prime is 77531779813. The reversal of 77531779782 is 28797713577.

77531779782 is a `hidden beast` number, since 7 + 7 + 531 + 7 + 7 + 97 + 8 + 2 = 666.

It is a super-2 number, since 2×77531779782² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2153660532 + ... + 2153660567.

It is an arithmetic number, because the mean of its divisors is an integer number (13998793575).

Almost surely, 2^77531779782 is an apocalyptic number.

77531779782 is an abundant number, since it is smaller than the sum of its proper divisors (90453743118).

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

77531779782 is a wasteful number, since it uses less digits than its factorization.

77531779782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4307321107 (or 4307321104 counting only the distinct ones).

The product of its digits is 36303120, while the sum is 63.

The spelling of 77531779782 in words is "seventy-seven billion, five hundred thirty-one million, seven hundred seventy-nine thousand, seven hundred eighty-two".