51394942409 has 2 divisors, whose sum is σ = 51394942410. Its totient is φ = 51394942408.

The previous prime is 51394942367. The next prime is 51394942429. The reversal of 51394942409 is 90424949315.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38417176009 + 12977766400 = 196003^2 + 113920^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51394942409 is a prime.

It is not a weakly prime, because it can be changed into another prime (51394942429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25697471204 + 25697471205.

It is an arithmetic number, because the mean of its divisors is an integer number (25697471205).

Almost surely, 2^51394942409 is an apocalyptic number.

It is an amenable number.

51394942409 is a deficient number, since it is larger than the sum of its proper divisors (1).

51394942409 is an equidigital number, since it uses as much as digits as its factorization.

51394942409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1399680, while the sum is 50.

The spelling of 51394942409 in words is "fifty-one billion, three hundred ninety-four million, nine hundred forty-two thousand, four hundred nine".