21018214 has 16 divisors (see below), whose sum is σ = 37274400. Its totient is φ = 8697024.

The previous prime is 21018211. The next prime is 21018227. The reversal of 21018214 is 41281012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21018191 and 21018200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21018211) 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 7 ways as a sum of consecutive naturals, for example, 25479 + ... + 26290.

It is an arithmetic number, because the mean of its divisors is an integer number (2329650).

Almost surely, 2^21018214 is an apocalyptic number.

21018214 is a deficient number, since it is larger than the sum of its proper divisors (16256186).

21018214 is a wasteful number, since it uses less digits than its factorization.

21018214 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51807.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 21018214 is about 4584.5625745539. The cubic root of 21018214 is about 275.9721581521.

Adding to 21018214 its reverse (41281012), we get a palindrome (62299226).

The spelling of 21018214 in words is "twenty-one million, eighteen thousand, two hundred fourteen".