21432242 has 12 divisors (see below), whose sum is σ = 34812090. Its totient is φ = 9891648.

The previous prime is 21432241. The next prime is 21432259. The reversal of 21432242 is 24223412.

It can be written as a sum of positive squares in 3 ways, for example, as 5424241 + 16008001 = 2329^2 + 4001^2 .

It is not an unprimeable number, because it can be changed into a prime (21432241) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 31367 + ... + 32042.

Almost surely, 2^21432242 is an apocalyptic number.

21432242 is a deficient number, since it is larger than the sum of its proper divisors (13379848).

21432242 is a wasteful number, since it uses less digits than its factorization.

21432242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63437 (or 63424 counting only the distinct ones).

The product of its digits is 768, while the sum is 20.

The square root of 21432242 is about 4629.4969489136. The cubic root of 21432242 is about 277.7724705238.

Adding to 21432242 its reverse (24223412), we get a palindrome (45655654).

The spelling of 21432242 in words is "twenty-one million, four hundred thirty-two thousand, two hundred forty-two".