21162517 has 2 divisors, whose sum is σ = 21162518. Its totient is φ = 21162516.

The previous prime is 21162503. The next prime is 21162521. The reversal of 21162517 is 71526112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18096516 + 3066001 = 4254^2 + 1751^2 .

It is a cyclic number.

It is not a de Polignac number, because 21162517 - 2¹⁵ = 21129749 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21162491 and 21162500.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21162217) 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 as a sum of consecutive naturals, namely, 10581258 + 10581259.

It is an arithmetic number, because the mean of its divisors is an integer number (10581259).

Almost surely, 2^21162517 is an apocalyptic number.

It is an amenable number.

21162517 is a deficient number, since it is larger than the sum of its proper divisors (1).

21162517 is an equidigital number, since it uses as much as digits as its factorization.

21162517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 840, while the sum is 25.

The square root of 21162517 is about 4600.2735788212. The cubic root of 21162517 is about 276.6022912753.

Adding to 21162517 its reverse (71526112), we get a palindrome (92688629).

The spelling of 21162517 in words is "twenty-one million, one hundred sixty-two thousand, five hundred seventeen".