21126442 has 24 divisors (see below), whose sum is σ = 34632900. Its totient is φ = 9652608.

The previous prime is 21126431. The next prime is 21126449. The reversal of 21126442 is 24462112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20967241 + 159201 = 4579^2 + 399^2 .

It is not an unprimeable number, because it can be changed into a prime (21126449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20434 + ... + 21442.

Almost surely, 2^21126442 is an apocalyptic number.

21126442 is a deficient number, since it is larger than the sum of its proper divisors (13506458).

21126442 is a wasteful number, since it uses less digits than its factorization.

21126442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1078 (or 1059 counting only the distinct ones).

The product of its digits is 768, while the sum is 22.

The square root of 21126442 is about 4596.3509439554. The cubic root of 21126442 is about 276.4450304764.

Adding to 21126442 its reverse (24462112), we get a palindrome (45588554).

The spelling of 21126442 in words is "twenty-one million, one hundred twenty-six thousand, four hundred forty-two".