1278058640405 has 4 divisors (see below), whose sum is σ = 1533670368492. Its totient is φ = 1022446912320.

The previous prime is 1278058640399. The next prime is 1278058640413. The reversal of 1278058640405 is 5040468508721.

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

It can be written as a sum of positive squares in 2 ways, for example, as 533120482801 + 744938157604 = 730151^2 + 863098^2 .

It is not a de Polignac number, because 1278058640405 - 2¹⁴ = 1278058624021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127805864036 + ... + 127805864045.

It is an arithmetic number, because the mean of its divisors is an integer number (383417592123).

Almost surely, 2^{1278058640405} is an apocalyptic number.

It is an amenable number.

1278058640405 is a deficient number, since it is larger than the sum of its proper divisors (255611728087).

1278058640405 is an equidigital number, since it uses as much as digits as its factorization.

1278058640405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255611728086.

The product of its (nonzero) digits is 2150400, while the sum is 50.

The spelling of 1278058640405 in words is "one trillion, two hundred seventy-eight billion, fifty-eight million, six hundred forty thousand, four hundred five".