1878805878361 has 4 divisors (see below), whose sum is σ = 1929584415652. Its totient is φ = 1828027341072.

The previous prime is 1878805878269. The next prime is 1878805878373. The reversal of 1878805878361 is 1638785088781.

It is a happy number.

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 801920250000 + 1076885628361 = 895500^2 + 1037731^2 .

It is a cyclic number.

It is not a de Polignac number, because 1878805878361 - 2²³ = 1878797489753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1878805876361) 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, 25389268590 + ... + 25389268663.

It is an arithmetic number, because the mean of its divisors is an integer number (482396103913).

Almost surely, 2^{1878805878361} is an apocalyptic number.

It is an amenable number.

1878805878361 is a deficient number, since it is larger than the sum of its proper divisors (50778537291).

1878805878361 is an equidigital number, since it uses as much as digits as its factorization.

1878805878361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50778537290.

The product of its (nonzero) digits is 144506880, while the sum is 70.

The spelling of 1878805878361 in words is "one trillion, eight hundred seventy-eight billion, eight hundred five million, eight hundred seventy-eight thousand, three hundred sixty-one".