51242837917 has 2 divisors, whose sum is σ = 51242837918. Its totient is φ = 51242837916.

The previous prime is 51242837791. The next prime is 51242837939. The reversal of 51242837917 is 71973824215.

Together with previous prime (51242837791) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28717030521 + 22525807396 = 169461^2 + 150086^2 .

It is a cyclic number.

It is not a de Polignac number, because 51242837917 - 2²³ = 51234449309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51242837617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25621418958 + 25621418959.

It is an arithmetic number, because the mean of its divisors is an integer number (25621418959).

Almost surely, 2^51242837917 is an apocalyptic number.

It is an amenable number.

51242837917 is a deficient number, since it is larger than the sum of its proper divisors (1).

51242837917 is an equidigital number, since it uses as much as digits as its factorization.

51242837917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 846720, while the sum is 49.

The spelling of 51242837917 in words is "fifty-one billion, two hundred forty-two million, eight hundred thirty-seven thousand, nine hundred seventeen".