51365221 has 2 divisors, whose sum is σ = 51365222. Its totient is φ = 51365220.

The previous prime is 51365201. The next prime is 51365261. The reversal of 51365221 is 12256315.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40068900 + 11296321 = 6330^2 + 3361^2 .

It is a cyclic number.

It is not a de Polignac number, because 51365221 - 2¹¹ = 51363173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51365201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25682610 + 25682611.

It is an arithmetic number, because the mean of its divisors is an integer number (25682611).

Almost surely, 2^51365221 is an apocalyptic number.

It is an amenable number.

51365221 is a deficient number, since it is larger than the sum of its proper divisors (1).

51365221 is an equidigital number, since it uses as much as digits as its factorization.

51365221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1800, while the sum is 25.

The square root of 51365221 is about 7166.9533973649. The cubic root of 51365221 is about 371.7260986242.

The spelling of 51365221 in words is "fifty-one million, three hundred sixty-five thousand, two hundred twenty-one".