21235445 has 32 divisors (see below), whose sum is σ = 33454080. Its totient is φ = 12536640.

The previous prime is 21235427. The next prime is 21235517. The reversal of 21235445 is 54453212.

It is a happy number.

It is not a de Polignac number, because 21235445 - 2¹⁴ = 21219061 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 5864 + ... + 8766.

It is an arithmetic number, because the mean of its divisors is an integer number (1045440).

Almost surely, 2^21235445 is an apocalyptic number.

It is an amenable number.

21235445 is a deficient number, since it is larger than the sum of its proper divisors (12218635).

21235445 is a wasteful number, since it uses less digits than its factorization.

21235445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2945.

The product of its digits is 4800, while the sum is 26.

The square root of 21235445 is about 4608.1932468159. The cubic root of 21235445 is about 276.9196593932.

Adding to 21235445 its reverse (54453212), we get a palindrome (75688657).

The spelling of 21235445 in words is "twenty-one million, two hundred thirty-five thousand, four hundred forty-five".