51863260721 has 2 divisors, whose sum is σ = 51863260722. Its totient is φ = 51863260720.

The previous prime is 51863260699. The next prime is 51863260723. The reversal of 51863260721 is 12706236815.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35283865600 + 16579395121 = 187840^2 + 128761^2 .

It is a cyclic number.

It is not a de Polignac number, because 51863260721 - 2³⁴ = 34683391537 is a prime.

It is a super-2 number, since 2×51863260721² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 51863260723, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (51863260723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25931630360 + 25931630361.

It is an arithmetic number, because the mean of its divisors is an integer number (25931630361).

Almost surely, 2^51863260721 is an apocalyptic number.

It is an amenable number.

51863260721 is a deficient number, since it is larger than the sum of its proper divisors (1).

51863260721 is an equidigital number, since it uses as much as digits as its factorization.

51863260721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 41.

The spelling of 51863260721 in words is "fifty-one billion, eight hundred sixty-three million, two hundred sixty thousand, seven hundred twenty-one".