21043023 has 8 divisors (see below), whose sum is σ = 28100736. Its totient is φ = 14007000.

The previous prime is 21043021. The next prime is 21043027. The reversal of 21043023 is 32034012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21043023 - 2¹ = 21043021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21042993 and 21043011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21043021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3003 + ... + 7148.

It is an arithmetic number, because the mean of its divisors is an integer number (3512592).

Almost surely, 2^21043023 is an apocalyptic number.

21043023 is a deficient number, since it is larger than the sum of its proper divisors (7057713).

21043023 is a wasteful number, since it uses less digits than its factorization.

21043023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10845.

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 21043023 is about 4587.2674872957. The cubic root of 21043023 is about 276.0806973652.

Adding to 21043023 its reverse (32034012), we get a palindrome (53077035).

The spelling of 21043023 in words is "twenty-one million, forty-three thousand, twenty-three".