21403117 has 2 divisors, whose sum is σ = 21403118. Its totient is φ = 21403116.

The previous prime is 21403111. The next prime is 21403159. The reversal of 21403117 is 71130412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19838116 + 1565001 = 4454^2 + 1251^2 .

It is a cyclic number.

It is not a de Polignac number, because 21403117 - 2¹¹ = 21401069 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21403094 and 21403103.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21403111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10701558 + 10701559.

It is an arithmetic number, because the mean of its divisors is an integer number (10701559).

Almost surely, 2^21403117 is an apocalyptic number.

It is an amenable number.

21403117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21403117 is an equidigital number, since it uses as much as digits as its factorization.

21403117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 21403117 is about 4626.3502893750. The cubic root of 21403117 is about 277.6465886769.

Adding to 21403117 its reverse (71130412), we get a palindrome (92533529).

The spelling of 21403117 in words is "twenty-one million, four hundred three thousand, one hundred seventeen".