21143545 has 8 divisors (see below), whose sum is σ = 25528896. Its totient is φ = 16810416.

The previous prime is 21143537. The next prime is 21143569. The reversal of 21143545 is 54534112.

It is a happy number.

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 21143545 - 2³ = 21143537 is a prime.

It is a super-3 number, since 3×21143545³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12157 + ... + 13786.

It is an arithmetic number, because the mean of its divisors is an integer number (3191112).

Almost surely, 2^21143545 is an apocalyptic number.

It is an amenable number.

21143545 is a deficient number, since it is larger than the sum of its proper divisors (4385351).

21143545 is a wasteful number, since it uses less digits than its factorization.

21143545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26111.

The product of its digits is 2400, while the sum is 25.

The square root of 21143545 is about 4598.2110651861. The cubic root of 21143545 is about 276.5196094339.

Adding to 21143545 its reverse (54534112), we get a palindrome (75677657).

The spelling of 21143545 in words is "twenty-one million, one hundred forty-three thousand, five hundred forty-five".