21034545 has 16 divisors (see below), whose sum is σ = 38463360. Its totient is φ = 9615744.

The previous prime is 21034543. The next prime is 21034561. The reversal of 21034545 is 54543012.

It is not a de Polignac number, because 21034545 - 2¹ = 21034543 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (21034543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 100060 + ... + 100269.

It is an arithmetic number, because the mean of its divisors is an integer number (2403960).

Almost surely, 2^21034545 is an apocalyptic number.

It is an amenable number.

21034545 is a deficient number, since it is larger than the sum of its proper divisors (17428815).

21034545 is a wasteful number, since it uses less digits than its factorization.

21034545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200344.

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 21034545 is about 4586.3433146680. The cubic root of 21034545 is about 276.0436157704.

Adding to 21034545 its reverse (54543012), we get a palindrome (75577557).

The spelling of 21034545 in words is "twenty-one million, thirty-four thousand, five hundred forty-five".