18878178805 has 4 divisors (see below), whose sum is σ = 22653814572. Its totient is φ = 15102543040.

The previous prime is 18878178799. The next prime is 18878178877. The reversal of 18878178805 is 50887187881.

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 3926024964 + 14952153841 = 62658^2 + 122279^2 .

It is not a de Polignac number, because 18878178805 - 2⁷ = 18878178677 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, 1887817876 + ... + 1887817885.

It is an arithmetic number, because the mean of its divisors is an integer number (5663453643).

Almost surely, 2^18878178805 is an apocalyptic number.

It is an amenable number.

18878178805 is a deficient number, since it is larger than the sum of its proper divisors (3775635767).

18878178805 is an equidigital number, since it uses as much as digits as its factorization.

18878178805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3775635766.

The product of its (nonzero) digits is 8028160, while the sum is 61.

The spelling of 18878178805 in words is "eighteen billion, eight hundred seventy-eight million, one hundred seventy-eight thousand, eight hundred five".