21600617 has 2 divisors, whose sum is σ = 21600618. Its totient is φ = 21600616.

The previous prime is 21600613. The next prime is 21600619. The reversal of 21600617 is 71600612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21058921 + 541696 = 4589^2 + 736^2 .

It is a cyclic number.

It is not a de Polignac number, because 21600617 - 2² = 21600613 is a prime.

Together with 21600619, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21600592 and 21600601.

It is not a weakly prime, because it can be changed into another prime (21600613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10800308 + 10800309.

It is an arithmetic number, because the mean of its divisors is an integer number (10800309).

Almost surely, 2^21600617 is an apocalyptic number.

It is an amenable number.

21600617 is a deficient number, since it is larger than the sum of its proper divisors (1).

21600617 is an equidigital number, since it uses as much as digits as its factorization.

21600617 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 21600617 is about 4647.6463936061. The cubic root of 21600617 is about 278.4979817140.

The spelling of 21600617 in words is "twenty-one million, six hundred thousand, six hundred seventeen".