21016043 has 8 divisors (see below), whose sum is σ = 22231968. Its totient is φ = 19825344.

The previous prime is 21016031. The next prime is 21016049. The reversal of 21016043 is 34061012.

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 21016043 - 2⁴ = 21016027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21016049) 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 7 ways as a sum of consecutive naturals, for example, 4580 + ... + 7937.

It is an arithmetic number, because the mean of its divisors is an integer number (2778996).

Almost surely, 2^21016043 is an apocalyptic number.

21016043 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21016043 is a deficient number, since it is larger than the sum of its proper divisors (1215925).

21016043 is a wasteful number, since it uses less digits than its factorization.

21016043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12613.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21016043 is about 4584.3257955778. The cubic root of 21016043 is about 275.9626559780.

Adding to 21016043 its reverse (34061012), we get a palindrome (55077055).

The spelling of 21016043 in words is "twenty-one million, sixteen thousand, forty-three".