21369318 has 16 divisors (see below), whose sum is σ = 42787440. Its totient is φ = 7114976.

The previous prime is 21369311. The next prime is 21369329. The reversal of 21369318 is 81396312.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21369311) 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, 6268 + ... + 9056.

It is an arithmetic number, because the mean of its divisors is an integer number (2674215).

Almost surely, 2^21369318 is an apocalyptic number.

21369318 is an abundant number, since it is smaller than the sum of its proper divisors (21418122).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21369318 is a wasteful number, since it uses less digits than its factorization.

21369318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4071.

The product of its digits is 7776, while the sum is 33.

The square root of 21369318 is about 4622.6959666411. The cubic root of 21369318 is about 277.5003619831.

The spelling of 21369318 in words is "twenty-one million, three hundred sixty-nine thousand, three hundred eighteen".