7971632656 has 135 divisors (see below), whose sum is σ = 17943818133. Its totient is φ = 3428505600.

The previous prime is 7971632651. The next prime is 7971632659. The reversal of 7971632656 is 6562361797.

It is a happy number.

The square root of 7971632656 is 89284.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 671639056 + 7299993600 = 25916^2 + 85440^2 .

It is a super-2 number, since 2×7971632656² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (52).

It is a Duffinian number.

Its product of digits (2857680) is a multiple of the sum of its prime factors (270).

It is not an unprimeable number, because it can be changed into a prime (7971632651) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 78927006 + ... + 78927106.

Almost surely, 2^7971632656 is an apocalyptic number.

7971632656 is the 89284-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7971632656

7971632656 is an abundant number, since it is smaller than the sum of its proper divisors (9972185477).

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

7971632656 is a wasteful number, since it uses less digits than its factorization.

7971632656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270 (or 133 counting only the distinct ones).

The product of its digits is 2857680, while the sum is 52.

The cubic root of 7971632656 is about 1997.6332550306.

The spelling of 7971632656 in words is "seven billion, nine hundred seventy-one million, six hundred thirty-two thousand, six hundred fifty-six".