75665321 has 8 divisors (see below), whose sum is σ = 78382920. Its totient is φ = 72955008.

The previous prime is 75665309. The next prime is 75665323. The reversal of 75665321 is 12356657.

It can be written as a sum of positive squares in 4 ways, for example, as 47955625 + 27709696 = 6925^2 + 5264^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 75665321 - 2⁶ = 75665257 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 (75665323) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27605 + ... + 30221.

It is an arithmetic number, because the mean of its divisors is an integer number (9797865).

Almost surely, 2^75665321 is an apocalyptic number.

It is an amenable number.

75665321 is a deficient number, since it is larger than the sum of its proper divisors (2717599).

75665321 is a wasteful number, since it uses less digits than its factorization.

75665321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3643.

The product of its digits is 37800, while the sum is 35.

The square root of 75665321 is about 8698.5815510346. The cubic root of 75665321 is about 422.9596710355.

The spelling of 75665321 in words is "seventy-five million, six hundred sixty-five thousand, three hundred twenty-one".