21342243 has 8 divisors (see below), whose sum is σ = 30645328. Its totient is φ = 13133664.

The previous prime is 21342241. The next prime is 21342257. The reversal of 21342243 is 34224312.

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

It is not a de Polignac number, because 21342243 - 2¹ = 21342241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21342241) 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, 273580 + ... + 273657.

It is an arithmetic number, because the mean of its divisors is an integer number (3830666).

Almost surely, 2^21342243 is an apocalyptic number.

21342243 is a deficient number, since it is larger than the sum of its proper divisors (9303085).

21342243 is a wasteful number, since it uses less digits than its factorization.

21342243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 547253.

The product of its digits is 1152, while the sum is 21.

The square root of 21342243 is about 4619.7665525435. The cubic root of 21342243 is about 277.3831144779.

Adding to 21342243 its reverse (34224312), we get a palindrome (55566555).

The spelling of 21342243 in words is "twenty-one million, three hundred forty-two thousand, two hundred forty-three".