21849844 has 6 divisors (see below), whose sum is σ = 38237234. Its totient is φ = 10924920.

The previous prime is 21849809. The next prime is 21849857. The reversal of 21849844 is 44894812.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21734244 + 115600 = 4662^2 + 340^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21849797 and 21849806.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2731227 + ... + 2731234.

Almost surely, 2^21849844 is an apocalyptic number.

It is an amenable number.

21849844 is a deficient number, since it is larger than the sum of its proper divisors (16387390).

21849844 is a wasteful number, since it uses less digits than its factorization.

21849844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5462465 (or 5462463 counting only the distinct ones).

The product of its digits is 73728, while the sum is 40.

The square root of 21849844 is about 4674.3816703389. The cubic root of 21849844 is about 279.5649877737.

The spelling of 21849844 in words is "twenty-one million, eight hundred forty-nine thousand, eight hundred forty-four".