21254404 has 6 divisors (see below), whose sum is σ = 37195214. Its totient is φ = 10627200.

The previous prime is 21254399. The next prime is 21254411. The reversal of 21254404 is 40445212.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21252100 + 2304 = 4610^2 + 48^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2656797 + ... + 2656804.

Almost surely, 2^21254404 is an apocalyptic number.

It is an amenable number.

21254404 is a deficient number, since it is larger than the sum of its proper divisors (15940810).

21254404 is a wasteful number, since it uses less digits than its factorization.

21254404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5313605 (or 5313603 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 22.

The square root of 21254404 is about 4610.2498847676. The cubic root of 21254404 is about 277.0020461474.

Adding to 21254404 its reverse (40445212), we get a palindrome (61699616).

The spelling of 21254404 in words is "twenty-one million, two hundred fifty-four thousand, four hundred four".