21909546138 has 8 divisors (see below), whose sum is σ = 43819092288. Its totient is φ = 7303182044.

The previous prime is 21909546119. The next prime is 21909546151. The reversal of 21909546138 is 83164590912.

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

21909546138 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, 1825795506 + ... + 1825795517.

It is an arithmetic number, because the mean of its divisors is an integer number (5477386536).

Almost surely, 2^21909546138 is an apocalyptic number.

21909546138 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.

21909546138 is a wasteful number, since it uses less digits than its factorization.

21909546138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3651591028.

The product of its (nonzero) digits is 466560, while the sum is 48.

The spelling of 21909546138 in words is "twenty-one billion, nine hundred nine million, five hundred forty-six thousand, one hundred thirty-eight".