51913318409 has 2 divisors, whose sum is σ = 51913318410. Its totient is φ = 51913318408.

The previous prime is 51913318397. The next prime is 51913318411. The reversal of 51913318409 is 90481331915.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51868696009 + 44622400 = 227747^2 + 6680^2 .

It is a cyclic number.

It is not a de Polignac number, because 51913318409 - 2⁸ = 51913318153 is a prime.

Together with 51913318411, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51913318409.

It is not a weakly prime, because it can be changed into another prime (51913318609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25956659204 + 25956659205.

It is an arithmetic number, because the mean of its divisors is an integer number (25956659205).

Almost surely, 2^51913318409 is an apocalyptic number.

It is an amenable number.

51913318409 is a deficient number, since it is larger than the sum of its proper divisors (1).

51913318409 is an equidigital number, since it uses as much as digits as its factorization.

51913318409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640, while the sum is 44.

The spelling of 51913318409 in words is "fifty-one billion, nine hundred thirteen million, three hundred eighteen thousand, four hundred nine".