7891813840 has 80 divisors (see below), whose sum is σ = 18976928256. Its totient is φ = 3048998400.

The previous prime is 7891813793. The next prime is 7891813859. The reversal of 7891813840 is 483181987.

It is a tau number, because it is divible by the number of its divisors (80).

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, 1413294 + ... + 1418866.

Almost surely, 2^7891813840 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 7891813840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9488464128).

7891813840 is an abundant number, since it is smaller than the sum of its proper divisors (11085114416).

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

7891813840 is a wasteful number, since it uses less digits than its factorization.

7891813840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6188 (or 6182 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 49.

The square root of 7891813840 is about 88835.8814894072. The cubic root of 7891813840 is about 1990.9435388227.

The spelling of 7891813840 in words is "seven billion, eight hundred ninety-one million, eight hundred thirteen thousand, eight hundred forty".