21420241441 has 4 divisors (see below), whose sum is σ = 21425983252. Its totient is φ = 21414499632.

The previous prime is 21420241421. The next prime is 21420241471. The reversal of 21420241441 is 14414202412.

It is a happy number.

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 14684592400 + 6735649041 = 121180^2 + 82071^2 .

It is a cyclic number.

It is not a de Polignac number, because 21420241441 - 2¹³ = 21420233249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21420241421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2865306 + ... + 2872771.

It is an arithmetic number, because the mean of its divisors is an integer number (5356495813).

Almost surely, 2^21420241441 is an apocalyptic number.

It is an amenable number.

21420241441 is a deficient number, since it is larger than the sum of its proper divisors (5741811).

21420241441 is an equidigital number, since it uses as much as digits as its factorization.

21420241441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5741810.

The product of its (nonzero) digits is 2048, while the sum is 25.

Adding to 21420241441 its reverse (14414202412), we get a palindrome (35834443853).

The spelling of 21420241441 in words is "twenty-one billion, four hundred twenty million, two hundred forty-one thousand, four hundred forty-one".