21004218138 has 8 divisors (see below), whose sum is σ = 42008436288. Its totient is φ = 7001406044.

The previous prime is 21004218077. The next prime is 21004218187. The reversal of 21004218138 is 83181240012.

It is a sphenic number, since it is the product of 3 distinct primes.

21004218138 is an admirable 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, 1750351506 + ... + 1750351517.

It is an arithmetic number, because the mean of its divisors is an integer number (5251054536).

Almost surely, 2^21004218138 is an apocalyptic number.

21004218138 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21004218138 is a wasteful number, since it uses less digits than its factorization.

21004218138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3500703028.

The product of its (nonzero) digits is 3072, while the sum is 30.

The spelling of 21004218138 in words is "twenty-one billion, four million, two hundred eighteen thousand, one hundred thirty-eight".