7776641920 has 128 divisors (see below), whose sum is σ = 18870848640. Its totient is φ = 3064233984.

The previous prime is 7776641897. The next prime is 7776642019. The reversal of 7776641920 is 291466777.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21189577 + ... + 21189943.

It is an arithmetic number, because the mean of its divisors is an integer number (147428505).

Almost surely, 2^7776641920 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 7776641920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9435424320).

7776641920 is an abundant number, since it is smaller than the sum of its proper divisors (11094206720).

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

7776641920 is a wasteful number, since it uses less digits than its factorization.

7776641920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 792 (or 780 counting only the distinct ones).

The product of its (nonzero) digits is 889056, while the sum is 49.

The square root of 7776641920 is about 88185.2704253947. The cubic root of 7776641920 is about 1981.2108636068.

The spelling of 7776641920 in words is "seven billion, seven hundred seventy-six million, six hundred forty-one thousand, nine hundred twenty".