21043771 has 8 divisors (see below), whose sum is σ = 24088064. Its totient is φ = 18009000.

The previous prime is 21043753. The next prime is 21043793. The reversal of 21043771 is 17734012.

It is a happy number.

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 21043771 - 2⁹ = 21043259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21043171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3256 + ... + 7258.

It is an arithmetic number, because the mean of its divisors is an integer number (3011008).

Almost surely, 2^21043771 is an apocalyptic number.

21043771 is a deficient number, since it is larger than the sum of its proper divisors (3044293).

21043771 is an equidigital number, since it uses as much as digits as its factorization.

21043771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4761.

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 21043771 is about 4587.3490165890. The cubic root of 21043771 is about 276.0839685352.

Adding to 21043771 its reverse (17734012), we get a palindrome (38777783).

The spelling of 21043771 in words is "twenty-one million, forty-three thousand, seven hundred seventy-one".