21308071 has 8 divisors (see below), whose sum is σ = 21721104. Its totient is φ = 20899200.

The previous prime is 21308059. The next prime is 21308081. The reversal of 21308071 is 17080312.

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 21308071 - 2¹¹ = 21306023 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 (21308081) 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 7 ways as a sum of consecutive naturals, for example, 10480 + ... + 12346.

It is an arithmetic number, because the mean of its divisors is an integer number (2715138).

Almost surely, 2^21308071 is an apocalyptic number.

21308071 is a deficient number, since it is larger than the sum of its proper divisors (413033).

21308071 is a wasteful number, since it uses less digits than its factorization.

21308071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2081.

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 21308071 is about 4616.0666156372. The cubic root of 21308071 is about 277.2349919769.

Adding to 21308071 its reverse (17080312), we get a palindrome (38388383).

It can be divided in two parts, 2130 and 8071, that added together give a palindrome (10201).

The spelling of 21308071 in words is "twenty-one million, three hundred eight thousand, seventy-one".