1278288016961 has 2 divisors, whose sum is σ = 1278288016962. Its totient is φ = 1278288016960.

The previous prime is 1278288016949. The next prime is 1278288016997. The reversal of 1278288016961 is 1696108828721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1264007766961 + 14280250000 = 1124281^2 + 119500^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1278288016961 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1278288016961.

It is not a weakly prime, because it can be changed into another prime (1278288016861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639144008480 + 639144008481.

It is an arithmetic number, because the mean of its divisors is an integer number (639144008481).

Almost surely, 2^{1278288016961} is an apocalyptic number.

It is an amenable number.

1278288016961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278288016961 is an equidigital number, since it uses as much as digits as its factorization.

1278288016961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4644864, while the sum is 59.

The spelling of 1278288016961 in words is "one trillion, two hundred seventy-eight billion, two hundred eighty-eight million, sixteen thousand, nine hundred sixty-one".