21018063 has 12 divisors (see below), whose sum is σ = 30803864. Its totient is φ = 12738000.

The previous prime is 21018043. The next prime is 21018073. The reversal of 21018063 is 36081012.

It is not a de Polignac number, because 21018063 - 2¹³ = 21009871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21018043) 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 11 ways as a sum of consecutive naturals, for example, 28588 + ... + 29313.

Almost surely, 2^21018063 is an apocalyptic number.

21018063 is a deficient number, since it is larger than the sum of its proper divisors (9785801).

21018063 is a wasteful number, since it uses less digits than its factorization.

21018063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57926 (or 57915 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21018063 is about 4584.5461062138. The cubic root of 21018063 is about 275.9714972666.

Adding to 21018063 its reverse (36081012), we get a palindrome (57099075).

The spelling of 21018063 in words is "twenty-one million, eighteen thousand, sixty-three".