21474218 has 8 divisors (see below), whose sum is σ = 33906720. Its totient is φ = 10171980.

The previous prime is 21474217. The next prime is 21474223. The reversal of 21474218 is 81247412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21474218² = 922284077423048, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21474217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 282518 + ... + 282593.

It is an arithmetic number, because the mean of its divisors is an integer number (4238340).

Almost surely, 2^21474218 is an apocalyptic number.

21474218 is a deficient number, since it is larger than the sum of its proper divisors (12432502).

21474218 is a wasteful number, since it uses less digits than its factorization.

21474218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565132.

The product of its digits is 3584, while the sum is 29.

The square root of 21474218 is about 4634.0282692275. The cubic root of 21474218 is about 277.9536955123.

The spelling of 21474218 in words is "twenty-one million, four hundred seventy-four thousand, two hundred eighteen".