75665221 has 4 divisors (see below), whose sum is σ = 75696012. Its totient is φ = 75634432.

The previous prime is 75665209. The next prime is 75665231. The reversal of 75665221 is 12256657.

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 9828225 + 65836996 = 3135^2 + 8114^2 .

It is a cyclic number.

It is not a de Polignac number, because 75665221 - 2¹¹ = 75663173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (75665231) 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, 11356 + ... + 16741.

It is an arithmetic number, because the mean of its divisors is an integer number (18924003).

Almost surely, 2^75665221 is an apocalyptic number.

It is an amenable number.

75665221 is a deficient number, since it is larger than the sum of its proper divisors (30791).

75665221 is a wasteful number, since it uses less digits than its factorization.

75665221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30790.

The product of its digits is 25200, while the sum is 34.

The square root of 75665221 is about 8698.5758029691. The cubic root of 75665221 is about 422.9594847063.

The spelling of 75665221 in words is "seventy-five million, six hundred sixty-five thousand, two hundred twenty-one".