2178827843551 has 4 divisors (see below), whose sum is σ = 2178843997192. Its totient is φ = 2178811689912.

The previous prime is 2178827843519. The next prime is 2178827843573. The reversal of 2178827843551 is 1553487288712.

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

It is a cyclic number.

It is not a de Polignac number, because 2178827843551 - 2⁵ = 2178827843519 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2178827843551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2178827843251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7872780 + ... + 8144833.

It is an arithmetic number, because the mean of its divisors is an integer number (544710999298).

Almost surely, 2^{2178827843551} is an apocalyptic number.

2178827843551 is a deficient number, since it is larger than the sum of its proper divisors (16153641).

2178827843551 is a wasteful number, since it uses less digits than its factorization.

2178827843551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16153640.

The product of its digits is 30105600, while the sum is 61.

The spelling of 2178827843551 in words is "two trillion, one hundred seventy-eight billion, eight hundred twenty-seven million, eight hundred forty-three thousand, five hundred fifty-one".