21349546447 has 8 divisors (see below), whose sum is σ = 21620649600. Its totient is φ = 21080081880.

The previous prime is 21349546429. The next prime is 21349546481. The reversal of 21349546447 is 74464594312.

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 21349546447 - 2¹¹ = 21349544399 is a prime.

It is a super-2 number, since 2×21349546447² (a number of 21 digits) contains 22 as substring.

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 21349546447.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21349546487) 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, 383413 + ... + 435550.

It is an arithmetic number, because the mean of its divisors is an integer number (2702581200).

Almost surely, 2^21349546447 is an apocalyptic number.

21349546447 is a deficient number, since it is larger than the sum of its proper divisors (271103153).

21349546447 is a wasteful number, since it uses less digits than its factorization.

21349546447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 819293.

The product of its digits is 2903040, while the sum is 49.

The spelling of 21349546447 in words is "twenty-one billion, three hundred forty-nine million, five hundred forty-six thousand, four hundred forty-seven".