21143541 has 8 divisors (see below), whose sum is σ = 28355040. Its totient is φ = 14013872.

The previous prime is 21143537. The next prime is 21143569. The reversal of 21143541 is 14534112.

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 21143541 - 2² = 21143537 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21183541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19851 + ... + 20888.

It is an arithmetic number, because the mean of its divisors is an integer number (3544380).

Almost surely, 2^21143541 is an apocalyptic number.

It is an amenable number.

21143541 is a deficient number, since it is larger than the sum of its proper divisors (7211499).

21143541 is a wasteful number, since it uses less digits than its factorization.

21143541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40915.

The product of its digits is 480, while the sum is 21.

The square root of 21143541 is about 4598.2106302343. The cubic root of 21143541 is about 276.5195919963.

Adding to 21143541 its reverse (14534112), we get a palindrome (35677653).

The spelling of 21143541 in words is "twenty-one million, one hundred forty-three thousand, five hundred forty-one".