21418329 has 8 divisors (see below), whose sum is σ = 28589152. Its totient is φ = 14263200.

The previous prime is 21418261. The next prime is 21418333. The reversal of 21418329 is 92381412.

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

It is not a de Polignac number, because 21418329 - 2¹¹ = 21416281 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21418296 and 21418305.

It is not an unprimeable number, because it can be changed into a prime (21418349) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 244 + ... + 6549.

It is an arithmetic number, because the mean of its divisors is an integer number (3573644).

Almost surely, 2^21418329 is an apocalyptic number.

It is an amenable number.

21418329 is a deficient number, since it is larger than the sum of its proper divisors (7170823).

21418329 is a wasteful number, since it uses less digits than its factorization.

21418329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7847.

The product of its digits is 3456, while the sum is 30.

The square root of 21418329 is about 4627.9940579046. The cubic root of 21418329 is about 277.7123510560.

Adding to 21418329 its product of digits (3456), we get a triangular number (21421785 = T₆₅₄₅).

The spelling of 21418329 in words is "twenty-one million, four hundred eighteen thousand, three hundred twenty-nine".