51389955637 has 2 divisors, whose sum is σ = 51389955638. Its totient is φ = 51389955636.

The previous prime is 51389955601. The next prime is 51389955641. The reversal of 51389955637 is 73655998315.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39080940721 + 12309014916 = 197689^2 + 110946^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51389955637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51389955437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25694977818 + 25694977819.

It is an arithmetic number, because the mean of its divisors is an integer number (25694977819).

Almost surely, 2^51389955637 is an apocalyptic number.

It is an amenable number.

51389955637 is a deficient number, since it is larger than the sum of its proper divisors (1).

51389955637 is an equidigital number, since it uses as much as digits as its factorization.

51389955637 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30618000, while the sum is 61.

The spelling of 51389955637 in words is "fifty-one billion, three hundred eighty-nine million, nine hundred fifty-five thousand, six hundred thirty-seven".