21144541 has 8 divisors (see below), whose sum is σ = 23234400. Its totient is φ = 19082640.

The previous prime is 21144469. The next prime is 21144547. The reversal of 21144541 is 14544112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21144541 - 2⁹ = 21144029 is a prime.

It is a super-2 number, since 2×21144541² = 894183228201362, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21144547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5386 + ... + 8443.

It is an arithmetic number, because the mean of its divisors is an integer number (2904300).

Almost surely, 2^21144541 is an apocalyptic number.

It is an amenable number.

21144541 is a deficient number, since it is larger than the sum of its proper divisors (2089859).

21144541 is a wasteful number, since it uses less digits than its factorization.

21144541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13979.

The product of its digits is 640, while the sum is 22.

The square root of 21144541 is about 4598.3193668992. The cubic root of 21144541 is about 276.5239513297.

Adding to 21144541 its reverse (14544112), we get a palindrome (35688653).

The spelling of 21144541 in words is "twenty-one million, one hundred forty-four thousand, five hundred forty-one".