21243061 has 8 divisors (see below), whose sum is σ = 24346880. Its totient is φ = 18156528.

The previous prime is 21243059. The next prime is 21243077. The reversal of 21243061 is 16034212.

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 21243061 - 2¹ = 21243059 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243011) 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, 1566 + ... + 6703.

It is an arithmetic number, because the mean of its divisors is an integer number (3043360).

Almost surely, 2^21243061 is an apocalyptic number.

It is an amenable number.

21243061 is a deficient number, since it is larger than the sum of its proper divisors (3103819).

21243061 is an equidigital number, since it uses as much as digits as its factorization.

21243061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8643.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 21243061 is about 4609.0195269710. The cubic root of 21243061 is about 276.9527607801.

Adding to 21243061 its reverse (16034212), we get a palindrome (37277273).

The spelling of 21243061 in words is "twenty-one million, two hundred forty-three thousand, sixty-one".