21069843 has 8 divisors (see below), whose sum is σ = 28256208. Its totient is φ = 13965024.

The previous prime is 21069833. The next prime is 21069847. The reversal of 21069843 is 34896012.

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

It is not a de Polignac number, because 21069843 - 2¹² = 21065747 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21069847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19780 + ... + 20817.

It is an arithmetic number, because the mean of its divisors is an integer number (3532026).

Almost surely, 2^21069843 is an apocalyptic number.

21069843 is a deficient number, since it is larger than the sum of its proper divisors (7186365).

21069843 is a wasteful number, since it uses less digits than its factorization.

21069843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40773.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 21069843 is about 4590.1898653542. The cubic root of 21069843 is about 276.1979387708.

It can be divided in two parts, 21069 and 843, that added together give a palindrome (21912).

The spelling of 21069843 in words is "twenty-one million, sixty-nine thousand, eight hundred forty-three".