7826581644 has 144 divisors (see below), whose sum is σ = 21519187200. Its totient is φ = 2207399040.

The previous prime is 7826581643. The next prime is 7826581649. The reversal of 7826581644 is 4461856287.

It is a super-2 number, since 2×7826581644² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (7826581643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 24689374 + ... + 24689690.

It is an arithmetic number, because the mean of its divisors is an integer number (149438800).

Almost surely, 2^7826581644 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 7826581644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10759593600).

7826581644 is an abundant number, since it is smaller than the sum of its proper divisors (13692605556).

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

7826581644 is a wasteful number, since it uses less digits than its factorization.

7826581644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 748 (or 739 counting only the distinct ones).

The product of its digits is 2580480, while the sum is 51.

The square root of 7826581644 is about 88467.9695935201. The cubic root of 7826581644 is about 1985.4427709465.

The spelling of 7826581644 in words is "seven billion, eight hundred twenty-six million, five hundred eighty-one thousand, six hundred forty-four".