21171713 has 2 divisors, whose sum is σ = 21171714. Its totient is φ = 21171712.

The previous prime is 21171701. The next prime is 21171727. The reversal of 21171713 is 31717112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20948929 + 222784 = 4577^2 + 472^2 .

It is a cyclic number.

It is not a de Polignac number, because 21171713 - 2⁶ = 21171649 is a prime.

It is not a weakly prime, because it can be changed into another prime (21171743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10585856 + 10585857.

It is an arithmetic number, because the mean of its divisors is an integer number (10585857).

Almost surely, 2^21171713 is an apocalyptic number.

It is an amenable number.

21171713 is a deficient number, since it is larger than the sum of its proper divisors (1).

21171713 is an equidigital number, since it uses as much as digits as its factorization.

21171713 is an evil number, because the sum of its binary digits is even.

The product of its digits is 294, while the sum is 23.

The square root of 21171713 is about 4601.2729760361. The cubic root of 21171713 is about 276.6423505669.

Adding to 21171713 its reverse (31717112), we get a palindrome (52888825).

The spelling of 21171713 in words is "twenty-one million, one hundred seventy-one thousand, seven hundred thirteen".