21305141 has 16 divisors (see below), whose sum is σ = 25159680. Its totient is φ = 17785920.

The previous prime is 21305113. The next prime is 21305149. The reversal of 21305141 is 14150312.

It is a cyclic number.

It is not a de Polignac number, because 21305141 - 2¹⁰ = 21304117 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21305149) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54575 + ... + 54963.

It is an arithmetic number, because the mean of its divisors is an integer number (1572480).

Almost surely, 2^21305141 is an apocalyptic number.

It is an amenable number.

21305141 is a deficient number, since it is larger than the sum of its proper divisors (3854539).

21305141 is a wasteful number, since it uses less digits than its factorization.

21305141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 796.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 21305141 is about 4615.7492349563. The cubic root of 21305141 is about 277.2222841824. Note that the first 4 decimals are identical.

Adding to 21305141 its reverse (14150312), we get a palindrome (35455453).

The spelling of 21305141 in words is "twenty-one million, three hundred five thousand, one hundred forty-one".