21447353334 has 64 divisors (see below), whose sum is σ = 47522845440. Its totient is φ = 6452441160.

The previous prime is 21447353321. The next prime is 21447353371. The reversal of 21447353334 is 43335374412.

It is a junction number, because it is equal to n+sod(n) for n = 21447353292 and 21447353301.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 154297437 + ... + 154297575.

It is an arithmetic number, because the mean of its divisors is an integer number (742544460).

Almost surely, 2^21447353334 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21447353334, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23761422720).

21447353334 is an abundant number, since it is smaller than the sum of its proper divisors (26075492106).

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

21447353334 is an frugal number, since it uses more digits than its factorization.

21447353334 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455 (or 155 counting only the distinct ones).

The product of its digits is 362880, while the sum is 39.

The spelling of 21447353334 in words is "twenty-one billion, four hundred forty-seven million, three hundred fifty-three thousand, three hundred thirty-four".