21043006 has 4 divisors (see below), whose sum is σ = 31564512. Its totient is φ = 10521502.

The previous prime is 21042997. The next prime is 21043007. The reversal of 21043006 is 60034012.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21043007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5260750 + ... + 5260753.

It is an arithmetic number, because the mean of its divisors is an integer number (7891128).

Almost surely, 2^21043006 is an apocalyptic number.

21043006 is a deficient number, since it is larger than the sum of its proper divisors (10521506).

21043006 is a wasteful number, since it uses less digits than its factorization.

21043006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10521505.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 21043006 is about 4587.2656343404. The cubic root of 21043006 is about 276.0806230196.

Adding to 21043006 its reverse (60034012), we get a palindrome (81077018).

The spelling of 21043006 in words is "twenty-one million, forty-three thousand, six".