21716718 has 16 divisors (see below), whose sum is σ = 45988560. Its totient is φ = 6813056.

The previous prime is 21716713. The next prime is 21716729. The reversal of 21716718 is 81761712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21716713) 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, 106353 + ... + 106556.

It is an arithmetic number, because the mean of its divisors is an integer number (2874285).

Almost surely, 2^21716718 is an apocalyptic number.

21716718 is an abundant number, since it is smaller than the sum of its proper divisors (24271842).

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

21716718 is a wasteful number, since it uses less digits than its factorization.

21716718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212931.

The product of its digits is 4704, while the sum is 33.

The square root of 21716718 is about 4660.1199555376. The cubic root of 21716718 is about 278.9960560072.

The spelling of 21716718 in words is "twenty-one million, seven hundred sixteen thousand, seven hundred eighteen".