21033963 has 12 divisors (see below), whose sum is σ = 30811248. Its totient is φ = 13824720.

The previous prime is 21033941. The next prime is 21033967. The reversal of 21033963 is 36933012.

It is not a de Polignac number, because 21033963 - 2¹⁰ = 21032939 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21033967) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15820 + ... + 17097.

It is an arithmetic number, because the mean of its divisors is an integer number (2567604).

Almost surely, 2^21033963 is an apocalyptic number.

21033963 is a deficient number, since it is larger than the sum of its proper divisors (9777285).

21033963 is a wasteful number, since it uses less digits than its factorization.

21033963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32994 (or 32991 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 27.

The square root of 21033963 is about 4586.2798649886. The cubic root of 21033963 is about 276.0410698178.

Adding to 21033963 its reverse (36933012), we get a palindrome (57966975).

The spelling of 21033963 in words is "twenty-one million, thirty-three thousand, nine hundred sixty-three".