21120285 has 16 divisors (see below), whose sum is σ = 33943104. Its totient is φ = 11213952.

The previous prime is 21120283. The next prime is 21120311. The reversal of 21120285 is 58202112.

It is a happy number.

It is not a de Polignac number, because 21120285 - 2¹ = 21120283 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120283) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 474 + ... + 6516.

It is an arithmetic number, because the mean of its divisors is an integer number (2121444).

Almost surely, 2^21120285 is an apocalyptic number.

It is an amenable number.

21120285 is a deficient number, since it is larger than the sum of its proper divisors (12822819).

21120285 is a wasteful number, since it uses less digits than its factorization.

21120285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6284.

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 21120285 is about 4595.6811247083. The cubic root of 21120285 is about 276.4181725475.

Adding to 21120285 its reverse (58202112), we get a palindrome (79322397).

The spelling of 21120285 in words is "twenty-one million, one hundred twenty thousand, two hundred eighty-five".