21849884 has 36 divisors (see below), whose sum is σ = 45581760. Its totient is φ = 9132480.

The previous prime is 21849881. The next prime is 21849907. The reversal of 21849884 is 48894812.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21849881) 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 11 ways as a sum of consecutive naturals, for example, 6677 + ... + 9395.

It is an arithmetic number, because the mean of its divisors is an integer number (1266160).

Almost surely, 2^21849884 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21849884, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22790880).

21849884 is an abundant number, since it is smaller than the sum of its proper divisors (23731876).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21849884 is a wasteful number, since it uses less digits than its factorization.

21849884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2778 (or 2769 counting only the distinct ones).

The product of its digits is 147456, while the sum is 44.

The square root of 21849884 is about 4674.3859489777. The cubic root of 21849884 is about 279.5651583713.

The spelling of 21849884 in words is "twenty-one million, eight hundred forty-nine thousand, eight hundred eighty-four".