77984461640 has 64 divisors (see below), whose sum is σ = 180848021760. Its totient is φ = 30246151680.

The previous prime is 77984461619. The next prime is 77984461649. The reversal of 77984461640 is 4616448977.

It is not an unprimeable number, because it can be changed into a prime (77984461649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121457 + ... + 413183.

It is an arithmetic number, because the mean of its divisors is an integer number (2825750340).

Almost surely, 2^77984461640 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 77984461640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90424010880).

77984461640 is an abundant number, since it is smaller than the sum of its proper divisors (102863560120).

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

77984461640 is a wasteful number, since it uses less digits than its factorization.

77984461640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291942 (or 291938 counting only the distinct ones).

The product of its (nonzero) digits is 8128512, while the sum is 56.

The spelling of 77984461640 in words is "seventy-seven billion, nine hundred eighty-four million, four hundred sixty-one thousand, six hundred forty".