1378756742665 has 16 divisors (see below), whose sum is σ = 1664110889280. Its totient is φ = 1096606194880.

The previous prime is 1378756742663. The next prime is 1378756742687. The reversal of 1378756742665 is 5662476578731.

It is not a de Polignac number, because 1378756742665 - 2¹ = 1378756742663 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1378756742665.

It is not an unprimeable number, because it can be changed into a prime (1378756742663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4034247 + ... + 4362643.

It is an arithmetic number, because the mean of its divisors is an integer number (104006930580).

Almost surely, 2^{1378756742665} is an apocalyptic number.

It is an amenable number.

1378756742665 is a deficient number, since it is larger than the sum of its proper divisors (285354146615).

1378756742665 is a wasteful number, since it uses less digits than its factorization.

1378756742665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333272.

The product of its digits is 355622400, while the sum is 67.

The spelling of 1378756742665 in words is "one trillion, three hundred seventy-eight billion, seven hundred fifty-six million, seven hundred forty-two thousand, six hundred sixty-five".