21881842447 has 8 divisors (see below), whose sum is σ = 22085388000. Its totient is φ = 21679053024.

The previous prime is 21881842351. The next prime is 21881842459. The reversal of 21881842447 is 74424818812.

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

It is a cyclic number.

It is not a de Polignac number, because 21881842447 - 2⁷ = 21881842319 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21881842447.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21881842487) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130803 + ... + 246724.

It is an arithmetic number, because the mean of its divisors is an integer number (2760673500).

Almost surely, 2^21881842447 is an apocalyptic number.

21881842447 is a deficient number, since it is larger than the sum of its proper divisors (203545553).

21881842447 is a wasteful number, since it uses less digits than its factorization.

21881842447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378065.

The product of its digits is 917504, while the sum is 49.

The spelling of 21881842447 in words is "twenty-one billion, eight hundred eighty-one million, eight hundred forty-two thousand, four hundred forty-seven".