75707221 has 2 divisors, whose sum is σ = 75707222. Its totient is φ = 75707220.

The previous prime is 75707213. The next prime is 75707249. The reversal of 75707221 is 12270757.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60606225 + 15100996 = 7785^2 + 3886^2 .

It is an emirp because it is prime and its reverse (12270757) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 75707221 - 2³ = 75707213 is a prime.

It is a super-3 number, since 3×75707221³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (75707251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37853610 + 37853611.

It is an arithmetic number, because the mean of its divisors is an integer number (37853611).

Almost surely, 2^75707221 is an apocalyptic number.

It is an amenable number.

75707221 is a deficient number, since it is larger than the sum of its proper divisors (1).

75707221 is an equidigital number, since it uses as much as digits as its factorization.

75707221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6860, while the sum is 31.

The square root of 75707221 is about 8700.9896563552. The cubic root of 75707221 is about 423.0377285471.

Adding to 75707221 its reverse (12270757), we get a palindrome (87977978).

The spelling of 75707221 in words is "seventy-five million, seven hundred seven thousand, two hundred twenty-one".