77640439518 has 64 divisors (see below), whose sum is σ = 181804435200. Its totient is φ = 24492468960.

The previous prime is 77640439511. The next prime is 77640439529. The reversal of 77640439518 is 81593404677.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77640439511) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 957280 + ... + 1035212.

It is an arithmetic number, because the mean of its divisors is an integer number (2840694300).

Almost surely, 2^77640439518 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77640439518, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90902217600).

77640439518 is an abundant number, since it is smaller than the sum of its proper divisors (104163995682).

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

77640439518 is a wasteful number, since it uses less digits than its factorization.

77640439518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78934 (or 78928 counting only the distinct ones).

The product of its (nonzero) digits is 5080320, while the sum is 54.

The spelling of 77640439518 in words is "seventy-seven billion, six hundred forty million, four hundred thirty-nine thousand, five hundred eighteen".