18695978843 has 4 divisors (see below), whose sum is σ = 18696314400. Its totient is φ = 18695643288.

The previous prime is 18695978783. The next prime is 18695978849. The reversal of 18695978843 is 34887959681.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34887959681 = 757 ⋅46087133.

It is a cyclic number.

It is not a de Polignac number, because 18695978843 - 2¹⁶ = 18695913307 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18695978849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61955 + ... + 203052.

It is an arithmetic number, because the mean of its divisors is an integer number (4674078600).

Almost surely, 2^18695978843 is an apocalyptic number.

18695978843 is a deficient number, since it is larger than the sum of its proper divisors (335557).

18695978843 is an equidigital number, since it uses as much as digits as its factorization.

18695978843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335556.

The product of its digits is 104509440, while the sum is 68.

The spelling of 18695978843 in words is "eighteen billion, six hundred ninety-five million, nine hundred seventy-eight thousand, eight hundred forty-three".