7975728109 has 4 divisors (see below), whose sum is σ = 8444888604. Its totient is φ = 7506567616.

The previous prime is 7975728091. The next prime is 7975728119. The reversal of 7975728109 is 9018275797.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6861637225 + 1114090884 = 82835^2 + 33378^2 .

It is a cyclic number.

It is not a de Polignac number, because 7975728109 - 2⁹ = 7975727597 is a prime.

It is a super-2 number, since 2×7975728109² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7975728109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7975728119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 234580222 + ... + 234580255.

It is an arithmetic number, because the mean of its divisors is an integer number (2111222151).

Almost surely, 2^7975728109 is an apocalyptic number.

It is an amenable number.

7975728109 is a deficient number, since it is larger than the sum of its proper divisors (469160495).

7975728109 is a wasteful number, since it uses less digits than its factorization.

7975728109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 469160494.

The product of its (nonzero) digits is 2222640, while the sum is 55.

The square root of 7975728109 is about 89306.9320321777. The cubic root of 7975728109 is about 1997.9752933899.

The spelling of 7975728109 in words is "seven billion, nine hundred seventy-five million, seven hundred twenty-eight thousand, one hundred nine".