4278538113665 has 4 divisors (see below), whose sum is σ = 5134245736404. Its totient is φ = 3422830490928.

The previous prime is 4278538113637. The next prime is 4278538113691. The reversal of 4278538113665 is 5663118358724.

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 1352645759089 + 2925892354576 = 1163033^2 + 1710524^2 .

It is a cyclic number.

It is not a de Polignac number, because 4278538113665 - 2²⁴ = 4278521336449 is a prime.

It is a Duffinian number.

It is a Curzon 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, 427853811362 + ... + 427853811371.

It is an arithmetic number, because the mean of its divisors is an integer number (1283561434101).

Almost surely, 2^{4278538113665} is an apocalyptic number.

It is an amenable number.

4278538113665 is a deficient number, since it is larger than the sum of its proper divisors (855707622739).

4278538113665 is an equidigital number, since it uses as much as digits as its factorization.

4278538113665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 855707622738.

The product of its digits is 29030400, while the sum is 59.

The spelling of 4278538113665 in words is "four trillion, two hundred seventy-eight billion, five hundred thirty-eight million, one hundred thirteen thousand, six hundred sixty-five".