7981536640 has 256 divisors, whose sum is σ = 23970816000. Its totient is φ = 2468782080.

The previous prime is 7981536617. The next prime is 7981536649. The reversal of 7981536640 is 466351897.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7981536649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7342177 + ... + 7343263.

It is an arithmetic number, because the mean of its divisors is an integer number (93636000).

Almost surely, 2^7981536640 is an apocalyptic number.

7981536640 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7981536640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11985408000).

7981536640 is an abundant number, since it is smaller than the sum of its proper divisors (15989279360).

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

7981536640 is a wasteful number, since it uses less digits than its factorization.

7981536640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1273 (or 1261 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 49.

The square root of 7981536640 is about 89339.4461590176. The cubic root of 7981536640 is about 1998.4602014812.

The spelling of 7981536640 in words is "seven billion, nine hundred eighty-one million, five hundred thirty-six thousand, six hundred forty".