21363261 has 8 divisors (see below), whose sum is σ = 28885824. Its totient is φ = 14041440.

The previous prime is 21363257. The next prime is 21363289. The reversal of 21363261 is 16236312.

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 21363261 - 2² = 21363257 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21363161) 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, 49936 + ... + 50361.

It is an arithmetic number, because the mean of its divisors is an integer number (3610728).

Almost surely, 2^21363261 is an apocalyptic number.

It is an amenable number.

21363261 is a deficient number, since it is larger than the sum of its proper divisors (7522563).

21363261 is a wasteful number, since it uses less digits than its factorization.

21363261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100371.

The product of its digits is 1296, while the sum is 24.

The square root of 21363261 is about 4622.0407830308. The cubic root of 21363261 is about 277.4741409229.

Adding to 21363261 its reverse (16236312), we get a palindrome (37599573).

The spelling of 21363261 in words is "twenty-one million, three hundred sixty-three thousand, two hundred sixty-one".