21353718 has 8 divisors (see below), whose sum is σ = 42707448. Its totient is φ = 7117904.

The previous prime is 21353711. The next prime is 21353737. The reversal of 21353718 is 81735312.

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

21353718 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21353711) 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, 1779471 + ... + 1779482.

It is an arithmetic number, because the mean of its divisors is an integer number (5338431).

Almost surely, 2^21353718 is an apocalyptic number.

21353718 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21353718 is a wasteful number, since it uses less digits than its factorization.

21353718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3558958.

The product of its digits is 5040, while the sum is 30.

The square root of 21353718 is about 4621.0083315225. The cubic root of 21353718 is about 277.4328187342.

The spelling of 21353718 in words is "twenty-one million, three hundred fifty-three thousand, seven hundred eighteen".