21272617 has 2 divisors, whose sum is σ = 21272618. Its totient is φ = 21272616.

The previous prime is 21272611. The next prime is 21272621. The reversal of 21272617 is 71627212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19501056 + 1771561 = 4416^2 + 1331^2 .

It is a cyclic number.

It is not a de Polignac number, because 21272617 - 2¹¹ = 21270569 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21272611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10636308 + 10636309.

It is an arithmetic number, because the mean of its divisors is an integer number (10636309).

Almost surely, 2^21272617 is an apocalyptic number.

It is an amenable number.

21272617 is a deficient number, since it is larger than the sum of its proper divisors (1).

21272617 is an equidigital number, since it uses as much as digits as its factorization.

21272617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2352, while the sum is 28.

The square root of 21272617 is about 4612.2247343337. The cubic root of 21272617 is about 277.0811450157.

Adding to 21272617 its reverse (71627212), we get a palindrome (92899829).

The spelling of 21272617 in words is "twenty-one million, two hundred seventy-two thousand, six hundred seventeen".