21716001 has 24 divisors (see below), whose sum is σ = 32082336. Its totient is φ = 14152320.

The previous prime is 21715999. The next prime is 21716017. The reversal of 21716001 is 10061712.

It is not a de Polignac number, because 21716001 - 2¹ = 21715999 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21716081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 133146 + ... + 133308.

It is an arithmetic number, because the mean of its divisors is an integer number (1336764).

Almost surely, 2^21716001 is an apocalyptic number.

It is an amenable number.

21716001 is a deficient number, since it is larger than the sum of its proper divisors (10366335).

21716001 is a wasteful number, since it uses less digits than its factorization.

21716001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 413 (or 410 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 18.

The square root of 21716001 is about 4660.0430255524. The cubic root of 21716001 is about 278.9929855253.

Adding to 21716001 its reverse (10061712), we get a palindrome (31777713).

The spelling of 21716001 in words is "twenty-one million, seven hundred sixteen thousand, one".