21818419 has 16 divisors (see below), whose sum is σ = 26047936. Its totient is φ = 17884800.

The previous prime is 21818417. The next prime is 21818431. The reversal of 21818419 is 91481812.

It is a cyclic number.

It is not a de Polignac number, because 21818419 - 2¹ = 21818417 is a prime.

It is a super-3 number, since 3×21818419³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21818417) 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, 15109 + ... + 16489.

It is an arithmetic number, because the mean of its divisors is an integer number (1627996).

Almost surely, 2^21818419 is an apocalyptic number.

21818419 is a deficient number, since it is larger than the sum of its proper divisors (4229517).

21818419 is a wasteful number, since it uses less digits than its factorization.

21818419 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1486.

The product of its digits is 4608, while the sum is 34.

The square root of 21818419 is about 4671.0190536970. The cubic root of 21818419 is about 279.4308976498.

The spelling of 21818419 in words is "twenty-one million, eight hundred eighteen thousand, four hundred nineteen".