21845347 has 4 divisors (see below), whose sum is σ = 21858496. Its totient is φ = 21832200.

The previous prime is 21845311. The next prime is 21845353. The reversal of 21845347 is 74354812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21845347 - 2¹¹ = 21843299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21845387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3648 + ... + 7549.

It is an arithmetic number, because the mean of its divisors is an integer number (5464624).

Almost surely, 2^21845347 is an apocalyptic number.

21845347 is a deficient number, since it is larger than the sum of its proper divisors (13149).

21845347 is a wasteful number, since it uses less digits than its factorization.

21845347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13148.

The product of its digits is 26880, while the sum is 34.

The square root of 21845347 is about 4673.9006193970. The cubic root of 21845347 is about 279.5458070112.

The spelling of 21845347 in words is "twenty-one million, eight hundred forty-five thousand, three hundred forty-seven".