21414245 has 4 divisors (see below), whose sum is σ = 25697100. Its totient is φ = 17131392.

The previous prime is 21414241. The next prime is 21414257. The reversal of 21414245 is 54241412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4456321 + 16957924 = 2111^2 + 4118^2 .

It is a cyclic number.

It is not a de Polignac number, because 21414245 - 2² = 21414241 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21414245.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21414241) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 2141420 + ... + 2141429.

It is an arithmetic number, because the mean of its divisors is an integer number (6424275).

Almost surely, 2^21414245 is an apocalyptic number.

It is an amenable number.

21414245 is a deficient number, since it is larger than the sum of its proper divisors (4282855).

21414245 is an equidigital number, since it uses as much as digits as its factorization.

21414245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4282854.

The product of its digits is 1280, while the sum is 23.

The square root of 21414245 is about 4627.5528089909. The cubic root of 21414245 is about 277.6946987400.

Adding to 21414245 its reverse (54241412), we get a palindrome (75655657).

The spelling of 21414245 in words is "twenty-one million, four hundred fourteen thousand, two hundred forty-five".