17420421 has 4 divisors (see below), whose sum is σ = 23227232. Its totient is φ = 11613612.

The previous prime is 17420401. The next prime is 17420423. The reversal of 17420421 is 12402471.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 17420421 - 2¹⁵ = 17387653 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17420423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2903401 + ... + 2903406.

It is an arithmetic number, because the mean of its divisors is an integer number (5806808).

Almost surely, 2^17420421 is an apocalyptic number.

It is an amenable number.

17420421 is a deficient number, since it is larger than the sum of its proper divisors (5806811).

17420421 is an equidigital number, since it uses as much as digits as its factorization.

17420421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5806810.

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 17420421 is about 4173.7777851726. Note that the first 4 decimals coincide. The cubic root of 17420421 is about 259.2305704065.

Adding to 17420421 its reverse (12402471), we get a palindrome (29822892).

The spelling of 17420421 in words is "seventeen million, four hundred twenty thousand, four hundred twenty-one".