21300641 has 4 divisors (see below), whose sum is σ = 21876372. Its totient is φ = 20724912.

The previous prime is 21300619. The next prime is 21300649. The reversal of 21300641 is 14600312.

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 9740641 + 11560000 = 3121^2 + 3400^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21300641 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21300649) 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, 287810 + ... + 287883.

It is an arithmetic number, because the mean of its divisors is an integer number (5469093).

Almost surely, 2^21300641 is an apocalyptic number.

It is an amenable number.

21300641 is a deficient number, since it is larger than the sum of its proper divisors (575731).

21300641 is an equidigital number, since it uses as much as digits as its factorization.

21300641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 575730.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21300641 is about 4615.2617477235. The cubic root of 21300641 is about 277.2027648229.

Adding to 21300641 its reverse (14600312), we get a palindrome (35900953).

The spelling of 21300641 in words is "twenty-one million, three hundred thousand, six hundred forty-one".