21118986899 has 4 divisors (see below), whose sum is σ = 22361280264. Its totient is φ = 19876693536.

The previous prime is 21118986887. The next prime is 21118986907. The reversal of 21118986899 is 99868981112.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21118986899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21118986829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 621146657 + ... + 621146690.

It is an arithmetic number, because the mean of its divisors is an integer number (5590320066).

Almost surely, 2^21118986899 is an apocalyptic number.

21118986899 is a deficient number, since it is larger than the sum of its proper divisors (1242293365).

21118986899 is a wasteful number, since it uses less digits than its factorization.

21118986899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1242293364.

The product of its digits is 4478976, while the sum is 62.

The spelling of 21118986899 in words is "twenty-one billion, one hundred eighteen million, nine hundred eighty-six thousand, eight hundred ninety-nine".