77809757844 has 144 divisors (see below), whose sum is σ = 225810872448. Its totient is φ = 20307013632.

The previous prime is 77809757833. The next prime is 77809757899. The reversal of 77809757844 is 44875790877.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10270842 + ... + 10278414.

Almost surely, 2^77809757844 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 77809757844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112905436224).

77809757844 is an abundant number, since it is smaller than the sum of its proper divisors (148001114604).

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

77809757844 is a wasteful number, since it uses less digits than its factorization.

77809757844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7794 (or 7695 counting only the distinct ones).

The product of its (nonzero) digits is 110638080, while the sum is 66.

The spelling of 77809757844 in words is "seventy-seven billion, eight hundred nine million, seven hundred fifty-seven thousand, eight hundred forty-four".