9918780878199 has 4 divisors (see below), whose sum is σ = 13225041170936. Its totient is φ = 6612520585464.

The previous prime is 9918780878197. The next prime is 9918780878231.

It is a happy number.

9918780878199 is nontrivially palindromic in base 10.

9918780878199 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 9918780878199 - 2¹ = 9918780878197 is a prime.

It is a super-2 number, since 2×9918780878199² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9918780878197) 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, 1653130146364 + ... + 1653130146369.

It is an arithmetic number, because the mean of its divisors is an integer number (3306260292734).

Almost surely, 2^{9918780878199} is an apocalyptic number.

9918780878199 is a deficient number, since it is larger than the sum of its proper divisors (3306260292737).

9918780878199 is a wasteful number, since it uses less digits than its factorization.

9918780878199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3306260292736.

The product of its (nonzero) digits is 1316818944, while the sum is 84.

The spelling of 9918780878199 in words is "nine trillion, nine hundred eighteen billion, seven hundred eighty million, eight hundred seventy-eight thousand, one hundred ninety-nine".