21245235 has 32 divisors (see below), whose sum is σ = 37290240. Its totient is φ = 10243200.

The previous prime is 21245227. The next prime is 21245281. The reversal of 21245235 is 53254212.

It is not a de Polignac number, because 21245235 - 2³ = 21245227 is a prime.

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, 54421 + ... + 54809.

It is an arithmetic number, because the mean of its divisors is an integer number (1165320).

Almost surely, 2^21245235 is an apocalyptic number.

21245235 is a deficient number, since it is larger than the sum of its proper divisors (16045005).

21245235 is a wasteful number, since it uses less digits than its factorization.

21245235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 739.

The product of its digits is 2400, while the sum is 24.

The square root of 21245235 is about 4609.2553628542. The cubic root of 21245235 is about 276.9622081751.

Adding to 21245235 its reverse (53254212), we get a palindrome (74499447).

The spelling of 21245235 in words is "twenty-one million, two hundred forty-five thousand, two hundred thirty-five".