756689221 has 2 divisors, whose sum is σ = 756689222. Its totient is φ = 756689220.

The previous prime is 756689209. The next prime is 756689243. The reversal of 756689221 is 122986657.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 494573121 + 262116100 = 22239^2 + 16190^2 .

It is an emirp because it is prime and its reverse (122986657) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 756689221 - 2¹⁷ = 756558149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (756689281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 378344610 + 378344611.

It is an arithmetic number, because the mean of its divisors is an integer number (378344611).

Almost surely, 2^756689221 is an apocalyptic number.

It is an amenable number.

756689221 is a deficient number, since it is larger than the sum of its proper divisors (1).

756689221 is an equidigital number, since it uses as much as digits as its factorization.

756689221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 46.

The square root of 756689221 is about 27507.9846771806. The cubic root of 756689221 is about 911.2534435740.

The spelling of 756689221 in words is "seven hundred fifty-six million, six hundred eighty-nine thousand, two hundred twenty-one".