21031043 has 16 divisors (see below), whose sum is σ = 24675840. Its totient is φ = 17719200.

The previous prime is 21031033. The next prime is 21031063. The reversal of 21031043 is 34013012.

It is a cyclic number.

It is not a de Polignac number, because 21031043 - 2⁴ = 21031027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21031033) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8753 + ... + 10893.

It is an arithmetic number, because the mean of its divisors is an integer number (1542240).

Almost surely, 2^21031043 is an apocalyptic number.

21031043 is a deficient number, since it is larger than the sum of its proper divisors (3644797).

21031043 is a wasteful number, since it uses less digits than its factorization.

21031043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2218.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21031043 is about 4585.9615131399. The cubic root of 21031043 is about 276.0282956007.

Adding to 21031043 its reverse (34013012), we get a palindrome (55044055).

The spelling of 21031043 in words is "twenty-one million, thirty-one thousand, forty-three".