1278389556602 has 4 divisors (see below), whose sum is σ = 1917584334906. Its totient is φ = 639194778300.

The previous prime is 1278389556599. The next prime is 1278389556683. The reversal of 1278389556602 is 2066559838721.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1153065768481 + 125323788121 = 1073809^2 + 354011^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319597389149 + ... + 319597389152.

Almost surely, 2^{1278389556602} is an apocalyptic number.

1278389556602 is a deficient number, since it is larger than the sum of its proper divisors (639194778304).

1278389556602 is an equidigital number, since it uses as much as digits as its factorization.

1278389556602 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 639194778303.

The product of its (nonzero) digits is 43545600, while the sum is 62.

The spelling of 1278389556602 in words is "one trillion, two hundred seventy-eight billion, three hundred eighty-nine million, five hundred fifty-six thousand, six hundred two".