21033023 has 4 divisors (see below), whose sum is σ = 22945128. Its totient is φ = 19120920.

The previous prime is 21033011. The next prime is 21033053. The reversal of 21033023 is 32033012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21033023 - 2⁴ = 21033007 is a prime.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a junction number, because it is equal to n+sod(n) for n = 21032989 and 21033007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033053) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 956036 + ... + 956057.

It is an arithmetic number, because the mean of its divisors is an integer number (5736282).

Almost surely, 2^21033023 is an apocalyptic number.

21033023 is a deficient number, since it is larger than the sum of its proper divisors (1912105).

21033023 is a wasteful number, since it uses less digits than its factorization.

21033023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1912104.

The product of its (nonzero) digits is 108, while the sum is 14.

The square root of 21033023 is about 4586.1773842711. The cubic root of 21033023 is about 276.0369576989.

Adding to 21033023 its reverse (32033012), we get a palindrome (53066035).

It can be divided in two parts, 210 and 33023, that added together give a palindrome (33233).

The spelling of 21033023 in words is "twenty-one million, thirty-three thousand, twenty-three".