21242330 has 8 divisors (see below), whose sum is σ = 38236212. Its totient is φ = 8496928.

The previous prime is 21242237. The next prime is 21242339. The reversal of 21242330 is 3324212.

It can be written as a sum of positive squares in 2 ways, for example, as 19775809 + 1466521 = 4447^2 + 1211^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 21242299 and 21242308.

It is not an unprimeable number, because it can be changed into a prime (21242339) 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, 1062107 + ... + 1062126.

Almost surely, 2^21242330 is an apocalyptic number.

21242330 is a deficient number, since it is larger than the sum of its proper divisors (16993882).

21242330 is a wasteful number, since it uses less digits than its factorization.

21242330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2124240.

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 21242330 is about 4608.9402252579. The cubic root of 21242330 is about 276.9495839813.

Adding to 21242330 its reverse (3324212), we get a palindrome (24566542).

The spelling of 21242330 in words is "twenty-one million, two hundred forty-two thousand, three hundred thirty".