21245546 has 48 divisors (see below), whose sum is σ = 39787200. Its totient is φ = 8329728.

The previous prime is 21245533. The next prime is 21245557. The reversal of 21245546 is 64554212.

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 23 ways as a sum of consecutive naturals, for example, 238670 + ... + 238758.

It is an arithmetic number, because the mean of its divisors is an integer number (828900).

Almost surely, 2^21245546 is an apocalyptic number.

21245546 is a deficient number, since it is larger than the sum of its proper divisors (18541654).

21245546 is a wasteful number, since it uses less digits than its factorization.

21245546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191 (or 174 counting only the distinct ones).

The product of its digits is 9600, while the sum is 29.

The square root of 21245546 is about 4609.2890991996. The cubic root of 21245546 is about 276.9635596127.

Adding to 21245546 its reverse (64554212), we get a palindrome (85799758).

The spelling of 21245546 in words is "twenty-one million, two hundred forty-five thousand, five hundred forty-six".