21234021 has 8 divisors (see below), whose sum is σ = 28700160. Its totient is φ = 13961952.

The previous prime is 21234013. The next prime is 21234029. The reversal of 21234021 is 12043212.

It is an interprime number because it is at equal distance from previous prime (21234013) and next prime (21234029).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21234021 - 2³ = 21234013 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21234029) 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, 48261 + ... + 48698.

It is an arithmetic number, because the mean of its divisors is an integer number (3587520).

Almost surely, 2^21234021 is an apocalyptic number.

It is an amenable number.

21234021 is a deficient number, since it is larger than the sum of its proper divisors (7466139).

21234021 is an equidigital number, since it uses as much as digits as its factorization.

21234021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97035.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21234021 is about 4608.0387368163. The cubic root of 21234021 is about 276.9134693901.

Adding to 21234021 its reverse (12043212), we get a palindrome (33277233).

The spelling of 21234021 in words is "twenty-one million, two hundred thirty-four thousand, twenty-one".