21368718 has 32 divisors (see below), whose sum is σ = 54270720. Its totient is φ = 6105240.

The previous prime is 21368713. The next prime is 21368723. The reversal of 21368718 is 81786312.

It is an interprime number because it is at equal distance from previous prime (21368713) and next prime (21368723).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21368713) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27888 + ... + 28643.

It is an arithmetic number, because the mean of its divisors is an integer number (1695960).

Almost surely, 2^21368718 is an apocalyptic number.

21368718 is an abundant number, since it is smaller than the sum of its proper divisors (32902002).

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

21368718 is a wasteful number, since it uses less digits than its factorization.

21368718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56549 (or 56543 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 21368718 is about 4622.6310689909. The cubic root of 21368718 is about 277.4977647738.

The spelling of 21368718 in words is "twenty-one million, three hundred sixty-eight thousand, seven hundred eighteen".