21417423 has 8 divisors (see below), whose sum is σ = 28581168. Its totient is φ = 14265984.

The previous prime is 21417377. The next prime is 21417437. The reversal of 21417423 is 32471412.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21417423 - 2⁶ = 21417359 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21417393 and 21417402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21417463) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2361 + ... + 6957.

It is an arithmetic number, because the mean of its divisors is an integer number (3572646).

Almost surely, 2^21417423 is an apocalyptic number.

21417423 is a deficient number, since it is larger than the sum of its proper divisors (7163745).

21417423 is a wasteful number, since it uses less digits than its factorization.

21417423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6153.

The product of its digits is 1344, while the sum is 24.

The square root of 21417423 is about 4627.8961742891. The cubic root of 21417423 is about 277.7084352364.

Adding to 21417423 its reverse (32471412), we get a palindrome (53888835).

The spelling of 21417423 in words is "twenty-one million, four hundred seventeen thousand, four hundred twenty-three".