21030023 has 8 divisors (see below), whose sum is σ = 24684192. Its totient is φ = 17538336.

The previous prime is 21030001. The next prime is 21030043. The reversal of 21030023 is 32003012.

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 21030023 - 2²² = 16835719 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21029986 and 21030013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21030043) 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, 40340 + ... + 40857.

It is an arithmetic number, because the mean of its divisors is an integer number (3085524).

Almost surely, 2^21030023 is an apocalyptic number.

21030023 is a deficient number, since it is larger than the sum of its proper divisors (3654169).

21030023 is an equidigital number, since it uses as much as digits as its factorization.

21030023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81241.

The product of its (nonzero) digits is 36, while the sum is 11.

The square root of 21030023 is about 4585.8503028337. The cubic root of 21030023 is about 276.0238330956.

Adding to 21030023 its reverse (32003012), we get a palindrome (53033035).

The spelling of 21030023 in words is "twenty-one million, thirty thousand, twenty-three".