21839441 has 12 divisors (see below), whose sum is σ = 24988572. Its totient is φ = 18970368.

The previous prime is 21839437. The next prime is 21839459. The reversal of 21839441 is 14493812.

21839441 = 3304² + 3305².

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 863041 + 20976400 = 929^2 + 4580^2 .

It is not a de Polignac number, because 21839441 - 2² = 21839437 is a prime.

It is a super-2 number, since 2×21839441² = 953922366384962, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21839398 and 21839407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21839401) 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, 851 + ... + 6663.

It is an arithmetic number, because the mean of its divisors is an integer number (2082381).

Almost surely, 2^21839441 is an apocalyptic number.

21839441 is the 3305-th centered square number.

It is an amenable number.

21839441 is a deficient number, since it is larger than the sum of its proper divisors (3149131).

21839441 is a wasteful number, since it uses less digits than its factorization.

21839441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5860 (or 5843 counting only the distinct ones).

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

The square root of 21839441 is about 4673.2687703576. The cubic root of 21839441 is about 279.5206125332.

The spelling of 21839441 in words is "twenty-one million, eight hundred thirty-nine thousand, four hundred forty-one".