21602145 has 16 divisors (see below), whose sum is σ = 36383040. Its totient is φ = 10914624.

The previous prime is 21602143. The next prime is 21602149. The reversal of 21602145 is 54120612.

It is not a de Polignac number, because 21602145 - 2¹ = 21602143 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21602143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37614 + ... + 38183.

It is an arithmetic number, because the mean of its divisors is an integer number (2273940).

Almost surely, 2^21602145 is an apocalyptic number.

It is an amenable number.

21602145 is a deficient number, since it is larger than the sum of its proper divisors (14780895).

21602145 is a wasteful number, since it uses less digits than its factorization.

21602145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75824.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 21602145 is about 4647.8107749778. The cubic root of 21602145 is about 278.5045484228.

Adding to 21602145 its reverse (54120612), we get a palindrome (75722757).

The spelling of 21602145 in words is "twenty-one million, six hundred two thousand, one hundred forty-five".