21245774 has 16 divisors (see below), whose sum is σ = 35244720. Its totient is φ = 9524160.

The previous prime is 21245773. The next prime is 21245779. The reversal of 21245774 is 47754212.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21245774.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21245771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5009 + ... + 8220.

It is an arithmetic number, because the mean of its divisors is an integer number (2202795).

Almost surely, 2^21245774 is an apocalyptic number.

21245774 is a deficient number, since it is larger than the sum of its proper divisors (13998946).

21245774 is a wasteful number, since it uses less digits than its factorization.

21245774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13315.

The product of its digits is 15680, while the sum is 32.

The square root of 21245774 is about 4609.3138317975. The cubic root of 21245774 is about 276.9645503688.

Adding to 21245774 its reverse (47754212), we get a palindrome (68999986).

The spelling of 21245774 in words is "twenty-one million, two hundred forty-five thousand, seven hundred seventy-four".