51347581993 has 2 divisors, whose sum is σ = 51347581994. Its totient is φ = 51347581992.

The previous prime is 51347581991. The next prime is 51347582029. The reversal of 51347581993 is 39918574315.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31174492969 + 20173089024 = 176563^2 + 142032^2 .

It is a cyclic number.

It is not a de Polignac number, because 51347581993 - 2¹ = 51347581991 is a prime.

Together with 51347581991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (51347581991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25673790996 + 25673790997.

It is an arithmetic number, because the mean of its divisors is an integer number (25673790997).

Almost surely, 2^51347581993 is an apocalyptic number.

It is an amenable number.

51347581993 is a deficient number, since it is larger than the sum of its proper divisors (1).

51347581993 is an equidigital number, since it uses as much as digits as its factorization.

51347581993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4082400, while the sum is 55.

The spelling of 51347581993 in words is "fifty-one billion, three hundred forty-seven million, five hundred eighty-one thousand, nine hundred ninety-three".