51405989449 has 2 divisors, whose sum is σ = 51405989450. Its totient is φ = 51405989448.

The previous prime is 51405989447. The next prime is 51405989497. The reversal of 51405989449 is 94498950415.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 34079006025 + 17326983424 = 184605^2 + 131632^2 .

It is a cyclic number.

It is not a de Polignac number, because 51405989449 - 2¹ = 51405989447 is a prime.

Together with 51405989447, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 51405989393 and 51405989402.

It is not a weakly prime, because it can be changed into another prime (51405989441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25702994724 + 25702994725.

It is an arithmetic number, because the mean of its divisors is an integer number (25702994725).

Almost surely, 2^51405989449 is an apocalyptic number.

It is an amenable number.

51405989449 is a deficient number, since it is larger than the sum of its proper divisors (1).

51405989449 is an equidigital number, since it uses as much as digits as its factorization.

51405989449 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9331200, while the sum is 58.

The spelling of 51405989449 in words is "fifty-one billion, four hundred five million, nine hundred eighty-nine thousand, four hundred forty-nine".