21230545 has 8 divisors (see below), whose sum is σ = 29116224. Its totient is φ = 14558064.

The previous prime is 21230537. The next prime is 21230549. The reversal of 21230545 is 54503212.

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 21230545 - 2³ = 21230537 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21230549) 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, 303259 + ... + 303328.

It is an arithmetic number, because the mean of its divisors is an integer number (3639528).

Almost surely, 2^21230545 is an apocalyptic number.

It is an amenable number.

21230545 is a deficient number, since it is larger than the sum of its proper divisors (7885679).

21230545 is an equidigital number, since it uses as much as digits as its factorization.

21230545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 606599.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 21230545 is about 4607.6615544113. The cubic root of 21230545 is about 276.8983583607.

Adding to 21230545 its reverse (54503212), we get a palindrome (75733757).

The spelling of 21230545 in words is "twenty-one million, two hundred thirty thousand, five hundred forty-five".