21260417 has 2 divisors, whose sum is σ = 21260418. Its totient is φ = 21260416.

The previous prime is 21260413. The next prime is 21260419. The reversal of 21260417 is 71406212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20421361 + 839056 = 4519^2 + 916^2 .

It is a cyclic number.

It is not a de Polignac number, because 21260417 - 2² = 21260413 is a prime.

Together with 21260419, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_1345343 and since 21260417 and 1345343 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 21260392 and 21260401.

It is not a weakly prime, because it can be changed into another prime (21260413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10630208 + 10630209.

It is an arithmetic number, because the mean of its divisors is an integer number (10630209).

Almost surely, 2^21260417 is an apocalyptic number.

It is an amenable number.

21260417 is a deficient number, since it is larger than the sum of its proper divisors (1).

21260417 is an equidigital number, since it uses as much as digits as its factorization.

21260417 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 21260417 is about 4610.9019724995. The cubic root of 21260417 is about 277.0281655382.

Adding to 21260417 its reverse (71406212), we get a palindrome (92666629).

The spelling of 21260417 in words is "twenty-one million, two hundred sixty thousand, four hundred seventeen".