21805297347 has 8 divisors (see below), whose sum is σ = 29116677456. Its totient is φ = 14515391072.

The previous prime is 21805297337. The next prime is 21805297369. The reversal of 21805297347 is 74379250812.

It is a happy number.

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 21805297347 - 2⁷ = 21805297219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21805297296 and 21805297305.

It is not an unprimeable number, because it can be changed into a prime (21805297337) 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, 5366088 + ... + 5370149.

It is an arithmetic number, because the mean of its divisors is an integer number (3639584682).

Almost surely, 2^21805297347 is an apocalyptic number.

21805297347 is a deficient number, since it is larger than the sum of its proper divisors (7311380109).

21805297347 is a wasteful number, since it uses less digits than its factorization.

21805297347 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10736917.

The product of its (nonzero) digits is 846720, while the sum is 48.

The spelling of 21805297347 in words is "twenty-one billion, eight hundred five million, two hundred ninety-seven thousand, three hundred forty-seven".