75760721 has 4 divisors (see below), whose sum is σ = 80217252. Its totient is φ = 71304192.

The previous prime is 75760709. The next prime is 75760739. The reversal of 75760721 is 12706757.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12706757 = 7 ⋅1815251.

It can be written as a sum of positive squares in 2 ways, for example, as 28302400 + 47458321 = 5320^2 + 6889^2 .

It is a cyclic number.

It is not a de Polignac number, because 75760721 - 2²⁶ = 8651857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (75760021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2228240 + ... + 2228273.

It is an arithmetic number, because the mean of its divisors is an integer number (20054313).

Almost surely, 2^75760721 is an apocalyptic number.

It is an amenable number.

75760721 is a deficient number, since it is larger than the sum of its proper divisors (4456531).

75760721 is a wasteful number, since it uses less digits than its factorization.

75760721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4456530.

The product of its (nonzero) digits is 20580, while the sum is 35.

The square root of 75760721 is about 8704.0634763310. The cubic root of 75760721 is about 423.1373543997.

The spelling of 75760721 in words is "seventy-five million, seven hundred sixty thousand, seven hundred twenty-one".