75657321 has 12 divisors (see below), whose sum is σ = 113330672. Its totient is φ = 50438052.

The previous prime is 75657301. The next prime is 75657331. The reversal of 75657321 is 12375657.

75657321 is a `hidden beast` number, since 7 + 565 + 73 + 21 = 666.

It is not a de Polignac number, because 75657321 - 2⁹ = 75656809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (75657301) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 155431 + ... + 155916.

Almost surely, 2^75657321 is an apocalyptic number.

It is an amenable number.

75657321 is a deficient number, since it is larger than the sum of its proper divisors (37673351).

75657321 is an equidigital number, since it uses as much as digits as its factorization.

75657321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311362 (or 311350 counting only the distinct ones).

The product of its digits is 44100, while the sum is 36.

The square root of 75657321 is about 8698.1216937911. The cubic root of 75657321 is about 422.9447641773.

The spelling of 75657321 in words is "seventy-five million, six hundred fifty-seven thousand, three hundred twenty-one".