21011713 has 2 divisors, whose sum is σ = 21011714. Its totient is φ = 21011712.

The previous prime is 21011693. The next prime is 21011741. The reversal of 21011713 is 31711012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13786369 + 7225344 = 3713^2 + 2688^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21011713 is a prime.

It is not a weakly prime, because it can be changed into another prime (21011413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505856 + 10505857.

It is an arithmetic number, because the mean of its divisors is an integer number (10505857).

Almost surely, 2^21011713 is an apocalyptic number.

It is an amenable number.

21011713 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011713 is an equidigital number, since it uses as much as digits as its factorization.

21011713 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42, while the sum is 16.

The square root of 21011713 is about 4583.8535098757. The cubic root of 21011713 is about 275.9437021979.

Adding to 21011713 its reverse (31711012), we get a palindrome (52722725).

The spelling of 21011713 in words is "twenty-one million, eleven thousand, seven hundred thirteen".