7821591072 has 96 divisors (see below), whose sum is σ = 21715787520. Its totient is φ = 2458149120.

The previous prime is 7821590989. The next prime is 7821591079. The reversal of 7821591072 is 2701951287.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×7821591072² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (7821591079) 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, 374703 + ... + 395025.

It is an arithmetic number, because the mean of its divisors is an integer number (226206120).

Almost surely, 2^7821591072 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 7821591072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10857893760).

7821591072 is an abundant number, since it is smaller than the sum of its proper divisors (13894196448).

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

7821591072 is a wasteful number, since it uses less digits than its factorization.

7821591072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20566 (or 20558 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 42.

The square root of 7821591072 is about 88439.7595654805. The cubic root of 7821591072 is about 1985.0206793989.

The spelling of 7821591072 in words is "seven billion, eight hundred twenty-one million, five hundred ninety-one thousand, seventy-two".