21716671 has 8 divisors (see below), whose sum is σ = 22196000. Its totient is φ = 21241440.

The previous prime is 21716659. The next prime is 21716683. The reversal of 21716671 is 17661712.

It is an interprime number because it is at equal distance from previous prime (21716659) and next prime (21716683).

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 21716671 - 2⁹ = 21716159 is a prime.

It is a super-2 number, since 2×21716671² = 943227598644482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21716371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11245 + ... + 13033.

It is an arithmetic number, because the mean of its divisors is an integer number (2774500).

Almost surely, 2^21716671 is an apocalyptic number.

21716671 is a deficient number, since it is larger than the sum of its proper divisors (479329).

21716671 is a wasteful number, since it uses less digits than its factorization.

21716671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2049.

The product of its digits is 3528, while the sum is 31.

The square root of 21716671 is about 4660.1149127463. The cubic root of 21716671 is about 278.9958547364.

The spelling of 21716671 in words is "twenty-one million, seven hundred sixteen thousand, six hundred seventy-one".