51864131509 has 2 divisors, whose sum is σ = 51864131510. Its totient is φ = 51864131508.

The previous prime is 51864131467. The next prime is 51864131533. The reversal of 51864131509 is 90513146815.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30222779409 + 21641352100 = 173847^2 + 147110^2 .

It is a cyclic number.

It is not a de Polignac number, because 51864131509 - 2¹³ = 51864123317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51864131609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25932065754 + 25932065755.

It is an arithmetic number, because the mean of its divisors is an integer number (25932065755).

Almost surely, 2^51864131509 is an apocalyptic number.

It is an amenable number.

51864131509 is a deficient number, since it is larger than the sum of its proper divisors (1).

51864131509 is an equidigital number, since it uses as much as digits as its factorization.

51864131509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 129600, while the sum is 43.

The spelling of 51864131509 in words is "fifty-one billion, eight hundred sixty-four million, one hundred thirty-one thousand, five hundred nine".