21948289 has 8 divisors (see below), whose sum is σ = 24591168. Its totient is φ = 19413360.

The previous prime is 21948263. The next prime is 21948293. The reversal of 21948289 is 98284912.

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 21948289 - 2¹¹ = 21946241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21948229) 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 7 ways as a sum of consecutive naturals, for example, 26557 + ... + 27370.

It is an arithmetic number, because the mean of its divisors is an integer number (3073896).

Almost surely, 2^21948289 is an apocalyptic number.

It is an amenable number.

21948289 is a deficient number, since it is larger than the sum of its proper divisors (2642879).

21948289 is a wasteful number, since it uses less digits than its factorization.

21948289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53975.

The product of its digits is 82944, while the sum is 43.

The square root of 21948289 is about 4684.9001056586. The cubic root of 21948289 is about 279.9842210496.

The spelling of 21948289 in words is "twenty-one million, nine hundred forty-eight thousand, two hundred eighty-nine".