51530331221 has 2 divisors, whose sum is σ = 51530331222. Its totient is φ = 51530331220.

The previous prime is 51530331187. The next prime is 51530331239. The reversal of 51530331221 is 12213303515.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30703800625 + 20826530596 = 175225^2 + 144314^2 .

It is a cyclic number.

It is not a de Polignac number, because 51530331221 - 2³⁴ = 34350462037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51530331421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25765165610 + 25765165611.

It is an arithmetic number, because the mean of its divisors is an integer number (25765165611).

Almost surely, 2^51530331221 is an apocalyptic number.

It is an amenable number.

51530331221 is a deficient number, since it is larger than the sum of its proper divisors (1).

51530331221 is an equidigital number, since it uses as much as digits as its factorization.

51530331221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2700, while the sum is 26.

Adding to 51530331221 its reverse (12213303515), we get a palindrome (63743634736).

The spelling of 51530331221 in words is "fifty-one billion, five hundred thirty million, three hundred thirty-one thousand, two hundred twenty-one".