21121417 has 2 divisors, whose sum is σ = 21121418. Its totient is φ = 21121416.

The previous prime is 21121411. The next prime is 21121453. The reversal of 21121417 is 71412112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20575296 + 546121 = 4536^2 + 739^2 .

It is a cyclic number.

It is not a de Polignac number, because 21121417 - 2¹¹ = 21119369 is a prime.

It is a super-2 number, since 2×21121417² = 892228512175778, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121394 and 21121403.

It is not a weakly prime, because it can be changed into another prime (21121411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560708 + 10560709.

It is an arithmetic number, because the mean of its divisors is an integer number (10560709).

Almost surely, 2^21121417 is an apocalyptic number.

It is an amenable number.

21121417 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121417 is an equidigital number, since it uses as much as digits as its factorization.

21121417 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112, while the sum is 19.

The square root of 21121417 is about 4595.8042821687. The cubic root of 21121417 is about 276.4231109244.

Adding to 21121417 its reverse (71412112), we get a palindrome (92533529).

The spelling of 21121417 in words is "twenty-one million, one hundred twenty-one thousand, four hundred seventeen".