75832721 has 4 divisors (see below), whose sum is σ = 77882292. Its totient is φ = 73783152.

The previous prime is 75832697. The next prime is 75832741. The reversal of 75832721 is 12723857.

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 69072721 + 6760000 = 8311^2 + 2600^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-75832721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (75832741) 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 3 ways as a sum of consecutive naturals, for example, 1024730 + ... + 1024803.

It is an arithmetic number, because the mean of its divisors is an integer number (19470573).

Almost surely, 2^75832721 is an apocalyptic number.

It is an amenable number.

75832721 is a deficient number, since it is larger than the sum of its proper divisors (2049571).

75832721 is a wasteful number, since it uses less digits than its factorization.

75832721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2049570.

The product of its digits is 23520, while the sum is 35.

The square root of 75832721 is about 8708.1984933739. The cubic root of 75832721 is about 423.2713563074.

The spelling of 75832721 in words is "seventy-five million, eight hundred thirty-two thousand, seven hundred twenty-one".