1278761329873 has 2 divisors, whose sum is σ = 1278761329874. Its totient is φ = 1278761329872.

The previous prime is 1278761329871. The next prime is 1278761329877. The reversal of 1278761329873 is 3789231678721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 813264883344 + 465496446529 = 901812^2 + 682273^2 .

It is a cyclic number.

It is not a de Polignac number, because 1278761329873 - 2¹ = 1278761329871 is a prime.

It is a super-2 number, since 2×1278761329873² (a number of 25 digits) contains 22 as substring.

Together with 1278761329871, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1278761329871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639380664936 + 639380664937.

It is an arithmetic number, because the mean of its divisors is an integer number (639380664937).

Almost surely, 2^{1278761329873} is an apocalyptic number.

It is an amenable number.

1278761329873 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278761329873 is an equidigital number, since it uses as much as digits as its factorization.

1278761329873 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42674688, while the sum is 64.

The spelling of 1278761329873 in words is "one trillion, two hundred seventy-eight billion, seven hundred sixty-one million, three hundred twenty-nine thousand, eight hundred seventy-three".