21242338 has 8 divisors (see below), whose sum is σ = 34314588. Its totient is φ = 9804144.

The previous prime is 21242237. The next prime is 21242339. The reversal of 21242338 is 83324212.

It can be written as a sum of positive squares in 2 ways, for example, as 21095649 + 146689 = 4593^2 + 383^2 .

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

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, 408481 + ... + 408532.

Almost surely, 2^21242338 is an apocalyptic number.

21242338 is a deficient number, since it is larger than the sum of its proper divisors (13072250).

21242338 is a wasteful number, since it uses less digits than its factorization.

21242338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 817028.

The product of its digits is 2304, while the sum is 25.

The square root of 21242338 is about 4608.9410931363. The cubic root of 21242338 is about 276.9496187483.

The spelling of 21242338 in words is "twenty-one million, two hundred forty-two thousand, three hundred thirty-eight".