21442474 has 16 divisors (see below), whose sum is σ = 34145928. Its totient is φ = 10063872.

The previous prime is 21442471. The next prime is 21442489. The reversal of 21442474 is 47424412.

It can be written as a sum of positive squares in 4 ways, for example, as 17581249 + 3861225 = 4193^2 + 1965^2 .

It is not an unprimeable number, because it can be changed into a prime (21442471) 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, 19072 + ... + 20164.

Almost surely, 2^21442474 is an apocalyptic number.

21442474 is a deficient number, since it is larger than the sum of its proper divisors (12703454).

21442474 is a wasteful number, since it uses less digits than its factorization.

21442474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1689.

The product of its digits is 7168, while the sum is 28.

The square root of 21442474 is about 4630.6019047204. The cubic root of 21442474 is about 277.8166674203.

Adding to 21442474 its reverse (47424412), we get a palindrome (68866886).

The spelling of 21442474 in words is "twenty-one million, four hundred forty-two thousand, four hundred seventy-four".