21843149 has 4 divisors (see below), whose sum is σ = 21858720. Its totient is φ = 21827580.

The previous prime is 21843131. The next prime is 21843167. The reversal of 21843149 is 94134812.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (21843131) and next prime (21843167).

It is a cyclic number.

It is not a de Polignac number, because 21843149 - 2¹² = 21839053 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21843449) 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, 5447 + ... + 8564.

It is an arithmetic number, because the mean of its divisors is an integer number (5464680).

Almost surely, 2^21843149 is an apocalyptic number.

It is an amenable number.

21843149 is a deficient number, since it is larger than the sum of its proper divisors (15571).

21843149 is a wasteful number, since it uses less digits than its factorization.

21843149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15570.

The product of its digits is 6912, while the sum is 32.

The square root of 21843149 is about 4673.6654779734. The cubic root of 21843149 is about 279.5364310665.

The spelling of 21843149 in words is "twenty-one million, eight hundred forty-three thousand, one hundred forty-nine".