75072521 has 2 divisors, whose sum is σ = 75072522. Its totient is φ = 75072520.

The previous prime is 75072499. The next prime is 75072523. The reversal of 75072521 is 12527057.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68641225 + 6431296 = 8285^2 + 2536^2 .

It is a cyclic number.

It is not a de Polignac number, because 75072521 - 2⁶ = 75072457 is a prime.

It is a Sophie Germain prime.

Together with 75072523, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (75072523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37536260 + 37536261.

It is an arithmetic number, because the mean of its divisors is an integer number (37536261).

Almost surely, 2^75072521 is an apocalyptic number.

It is an amenable number.

75072521 is a deficient number, since it is larger than the sum of its proper divisors (1).

75072521 is an equidigital number, since it uses as much as digits as its factorization.

75072521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4900, while the sum is 29.

The square root of 75072521 is about 8664.4400280687. The cubic root of 75072521 is about 421.8522145975.

Adding to 75072521 its reverse (12527057), we get a palindrome (87599578).

The spelling of 75072521 in words is "seventy-five million, seventy-two thousand, five hundred twenty-one".