21335145 has 64 divisors (see below), whose sum is σ = 39481344. Its totient is φ = 9757440.

The previous prime is 21335143. The next prime is 21335173. The reversal of 21335145 is 54153312.

It is not a de Polignac number, because 21335145 - 2¹ = 21335143 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21335141) 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 63 ways as a sum of consecutive naturals, for example, 300460 + ... + 300530.

It is an arithmetic number, because the mean of its divisors is an integer number (616896).

Almost surely, 2^21335145 is an apocalyptic number.

It is an amenable number.

21335145 is a deficient number, since it is larger than the sum of its proper divisors (18146199).

21335145 is a wasteful number, since it uses less digits than its factorization.

21335145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182.

The product of its digits is 1800, while the sum is 24.

The square root of 21335145 is about 4618.9982680231. The cubic root of 21335145 is about 277.3523603900.

Adding to 21335145 its reverse (54153312), we get a palindrome (75488457).

The spelling of 21335145 in words is "twenty-one million, three hundred thirty-five thousand, one hundred forty-five".