51636216637 has 2 divisors, whose sum is σ = 51636216638. Its totient is φ = 51636216636.

The previous prime is 51636216623. The next prime is 51636216673. The reversal of 51636216637 is 73661263615.

Together with next prime (51636216673) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49118083876 + 2518132761 = 221626^2 + 50181^2 .

It is a cyclic number.

It is not a de Polignac number, because 51636216637 - 2⁷ = 51636216509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51636216937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25818108318 + 25818108319.

It is an arithmetic number, because the mean of its divisors is an integer number (25818108319).

Almost surely, 2^51636216637 is an apocalyptic number.

It is an amenable number.

51636216637 is a deficient number, since it is larger than the sum of its proper divisors (1).

51636216637 is an equidigital number, since it uses as much as digits as its factorization.

51636216637 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 816480, while the sum is 46.

The spelling of 51636216637 in words is "fifty-one billion, six hundred thirty-six million, two hundred sixteen thousand, six hundred thirty-seven".