21716707 has 4 divisors (see below), whose sum is σ = 21739240. Its totient is φ = 21694176.

The previous prime is 21716693. The next prime is 21716713. The reversal of 21716707 is 70761712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21716707 - 2¹⁵ = 21683939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21716767) 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, 9753 + ... + 11770.

It is an arithmetic number, because the mean of its divisors is an integer number (5434810).

Almost surely, 2^21716707 is an apocalyptic number.

21716707 is a deficient number, since it is larger than the sum of its proper divisors (22533).

21716707 is a wasteful number, since it uses less digits than its factorization.

21716707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22532.

The product of its (nonzero) digits is 4116, while the sum is 31.

The square root of 21716707 is about 4660.1187753103. The cubic root of 21716707 is about 278.9960089013.

The spelling of 21716707 in words is "twenty-one million, seven hundred sixteen thousand, seven hundred seven".