21190417 has 2 divisors, whose sum is σ = 21190418. Its totient is φ = 21190416.

The previous prime is 21190409. The next prime is 21190427. The reversal of 21190417 is 71409112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20286016 + 904401 = 4504^2 + 951^2 .

It is a cyclic number.

It is not a de Polignac number, because 21190417 - 2³ = 21190409 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21190391 and 21190400.

It is not a weakly prime, because it can be changed into another prime (21190427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10595208 + 10595209.

It is an arithmetic number, because the mean of its divisors is an integer number (10595209).

Almost surely, 2^21190417 is an apocalyptic number.

It is an amenable number.

21190417 is a deficient number, since it is larger than the sum of its proper divisors (1).

21190417 is an equidigital number, since it uses as much as digits as its factorization.

21190417 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 21190417 is about 4603.3050083608. The cubic root of 21190417 is about 276.7237924974.

Adding to 21190417 its reverse (71409112), we get a palindrome (92599529).

The spelling of 21190417 in words is "twenty-one million, one hundred ninety thousand, four hundred seventeen".