21413617 has 2 divisors, whose sum is σ = 21413618. Its totient is φ = 21413616.

The previous prime is 21413611. The next prime is 21413641. The reversal of 21413617 is 71631412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13256881 + 8156736 = 3641^2 + 2856^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21413617 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21413591 and 21413600.

It is not a weakly prime, because it can be changed into another prime (21413611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10706808 + 10706809.

It is an arithmetic number, because the mean of its divisors is an integer number (10706809).

Almost surely, 2^21413617 is an apocalyptic number.

It is an amenable number.

21413617 is a deficient number, since it is larger than the sum of its proper divisors (1).

21413617 is an equidigital number, since it uses as much as digits as its factorization.

21413617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 25.

The square root of 21413617 is about 4627.4849540544. The cubic root of 21413617 is about 277.6919841299.

It can be divided in two parts, 214 and 13617, that added together give a palindrome (13831).

The spelling of 21413617 in words is "twenty-one million, four hundred thirteen thousand, six hundred seventeen".