21043310 has 16 divisors (see below), whose sum is σ = 38684736. Its totient is φ = 8238048.

The previous prime is 21043301. The next prime is 21043313. The reversal of 21043310 is 1334012.

It is a super-2 number, since 2×21043310² = 885641791512200, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21043313) 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, 21917 + ... + 22856.

It is an arithmetic number, because the mean of its divisors is an integer number (2417796).

Almost surely, 2^21043310 is an apocalyptic number.

21043310 is a deficient number, since it is larger than the sum of its proper divisors (17641426).

21043310 is a wasteful number, since it uses less digits than its factorization.

21043310 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44827.

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

The square root of 21043310 is about 4587.2987694285. The cubic root of 21043310 is about 276.0819524891.

Adding to 21043310 its reverse (1334012), we get a palindrome (22377322).

The spelling of 21043310 in words is "twenty-one million, forty-three thousand, three hundred ten".