51981673553 has 2 divisors, whose sum is σ = 51981673554. Its totient is φ = 51981673552.

The previous prime is 51981673409. The next prime is 51981673559. The reversal of 51981673553 is 35537618915.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30440827729 + 21540845824 = 174473^2 + 146768^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51981673553 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 51981673495 and 51981673504.

It is not a weakly prime, because it can be changed into another prime (51981673559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25990836776 + 25990836777.

It is an arithmetic number, because the mean of its divisors is an integer number (25990836777).

Almost surely, 2^51981673553 is an apocalyptic number.

It is an amenable number.

51981673553 is a deficient number, since it is larger than the sum of its proper divisors (1).

51981673553 is an equidigital number, since it uses as much as digits as its factorization.

51981673553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3402000, while the sum is 53.

The spelling of 51981673553 in words is "fifty-one billion, nine hundred eighty-one million, six hundred seventy-three thousand, five hundred fifty-three".