21363617 has 8 divisors (see below), whose sum is σ = 23339232. Its totient is φ = 19393600.

The previous prime is 21363613. The next prime is 21363637. The reversal of 21363617 is 71636312.

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 21363617 - 2² = 21363613 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21363617.

It is not an unprimeable number, because it can be changed into a prime (21363613) 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, 14258 + ... + 15684.

It is an arithmetic number, because the mean of its divisors is an integer number (2917404).

Almost surely, 2^21363617 is an apocalyptic number.

It is an amenable number.

21363617 is a deficient number, since it is larger than the sum of its proper divisors (1975615).

21363617 is a wasteful number, since it uses less digits than its factorization.

21363617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2799.

The product of its digits is 4536, while the sum is 29.

The square root of 21363617 is about 4622.0792939975. The cubic root of 21363617 is about 277.4756822020.

Adding to 21363617 its reverse (71636312), we get a palindrome (92999929).

The spelling of 21363617 in words is "twenty-one million, three hundred sixty-three thousand, six hundred seventeen".