21718685 has 8 divisors (see below), whose sum is σ = 26148096. Its totient is φ = 17317840.

The previous prime is 21718681. The next prime is 21718703. The reversal of 21718685 is 58681712.

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

It is not a de Polignac number, because 21718685 - 2² = 21718681 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21718681) 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, 5429 + ... + 8538.

It is an arithmetic number, because the mean of its divisors is an integer number (3268512).

Almost surely, 2^21718685 is an apocalyptic number.

It is an amenable number.

21718685 is a deficient number, since it is larger than the sum of its proper divisors (4429411).

21718685 is a wasteful number, since it uses less digits than its factorization.

21718685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14283.

The product of its digits is 26880, while the sum is 38.

The square root of 21718685 is about 4660.3309968284. The cubic root of 21718685 is about 279.0044791443.

The spelling of 21718685 in words is "twenty-one million, seven hundred eighteen thousand, six hundred eighty-five".