21317045 has 8 divisors (see below), whose sum is σ = 25608096. Its totient is φ = 17035216.

The previous prime is 21317041. The next prime is 21317081. The reversal of 21317045 is 54071312.

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

It is a cyclic number.

It is not a de Polignac number, because 21317045 - 2² = 21317041 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21317045.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21317041) 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, 4754 + ... + 8076.

It is an arithmetic number, because the mean of its divisors is an integer number (3201012).

Almost surely, 2^21317045 is an apocalyptic number.

It is an amenable number.

21317045 is a deficient number, since it is larger than the sum of its proper divisors (4291051).

21317045 is a wasteful number, since it uses less digits than its factorization.

21317045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4611.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 21317045 is about 4617.0385530121. The cubic root of 21317045 is about 277.2739061460.

Adding to 21317045 its reverse (54071312), we get a palindrome (75388357).

The spelling of 21317045 in words is "twenty-one million, three hundred seventeen thousand, forty-five".