780640344137 has 2 divisors, whose sum is σ = 780640344138. Its totient is φ = 780640344136.

The previous prime is 780640344079. The next prime is 780640344149. The reversal of 780640344137 is 731443046087.

Added to its reverse (731443046087) it gives a square (1512083390224 = 1229668²).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 452573725696 + 328066618441 = 672736^2 + 572771^2 .

It is a cyclic number.

It is not a de Polignac number, because 780640344137 - 2⁸ = 780640343881 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 780640344091 and 780640344100.

It is not a weakly prime, because it can be changed into another prime (780640344637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390320172068 + 390320172069.

It is an arithmetic number, because the mean of its divisors is an integer number (390320172069).

Almost surely, 2^780640344137 is an apocalyptic number.

It is an amenable number.

780640344137 is a deficient number, since it is larger than the sum of its proper divisors (1).

780640344137 is an equidigital number, since it uses as much as digits as its factorization.

780640344137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1354752, while the sum is 47.

Adding to 780640344137 its reverse (731443046087), we get a square (1512083390224 = 1229668²).

The spelling of 780640344137 in words is "seven hundred eighty billion, six hundred forty million, three hundred forty-four thousand, one hundred thirty-seven".