21416687 has 8 divisors (see below), whose sum is σ = 21723936. Its totient is φ = 21111552.

The previous prime is 21416683. The next prime is 21416701. The reversal of 21416687 is 78661412.

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

It is a cyclic number.

It is not a de Polignac number, because 21416687 - 2² = 21416683 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21416683) 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, 34403 + ... + 35019.

It is an arithmetic number, because the mean of its divisors is an integer number (2715492).

Almost surely, 2^21416687 is an apocalyptic number.

21416687 is a deficient number, since it is larger than the sum of its proper divisors (307249).

21416687 is a wasteful number, since it uses less digits than its factorization.

21416687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1057.

The product of its digits is 16128, while the sum is 35.

The square root of 21416687 is about 4627.8166558324. The cubic root of 21416687 is about 277.7052540920.

The spelling of 21416687 in words is "twenty-one million, four hundred sixteen thousand, six hundred eighty-seven".