51156533221 has 2 divisors, whose sum is σ = 51156533222. Its totient is φ = 51156533220.

The previous prime is 51156533203. The next prime is 51156533227. The reversal of 51156533221 is 12233565115.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43675148196 + 7481385025 = 208986^2 + 86495^2 .

It is a cyclic number.

It is not a de Polignac number, because 51156533221 - 2⁵ = 51156533189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51156533227) 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, 25578266610 + 25578266611.

It is an arithmetic number, because the mean of its divisors is an integer number (25578266611).

Almost surely, 2^51156533221 is an apocalyptic number.

It is an amenable number.

51156533221 is a deficient number, since it is larger than the sum of its proper divisors (1).

51156533221 is an equidigital number, since it uses as much as digits as its factorization.

51156533221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27000, while the sum is 34.

The spelling of 51156533221 in words is "fifty-one billion, one hundred fifty-six million, five hundred thirty-three thousand, two hundred twenty-one".