21433442 has 4 divisors (see below), whose sum is σ = 32150166. Its totient is φ = 10716720.

The previous prime is 21433441. The next prime is 21433453. The reversal of 21433442 is 24433412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 13920361 + 7513081 = 3731^2 + 2741^2 .

It is not an unprimeable number, because it can be changed into a prime (21433441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5358359 + ... + 5358362.

Almost surely, 2^21433442 is an apocalyptic number.

21433442 is a deficient number, since it is larger than the sum of its proper divisors (10716724).

21433442 is a wasteful number, since it uses less digits than its factorization.

21433442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10716723.

The product of its digits is 2304, while the sum is 23.

The square root of 21433442 is about 4629.6265508138. The cubic root of 21433442 is about 277.7776546251. Note that the first 3 decimals are identical.

Adding to 21433442 its reverse (24433412), we get a palindrome (45866854).

The spelling of 21433442 in words is "twenty-one million, four hundred thirty-three thousand, four hundred forty-two".