21266313 has 8 divisors (see below), whose sum is σ = 28380000. Its totient is φ = 14165088.

The previous prime is 21266299. The next prime is 21266317. The reversal of 21266313 is 31366212.

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 21266313 - 2¹³ = 21258121 is a prime.

It is a super-3 number, since 3×21266313³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21266317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2133 + ... + 6861.

It is an arithmetic number, because the mean of its divisors is an integer number (3547500).

Almost surely, 2^21266313 is an apocalyptic number.

It is an amenable number.

21266313 is a deficient number, since it is larger than the sum of its proper divisors (7113687).

21266313 is a wasteful number, since it uses less digits than its factorization.

21266313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6231.

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

The square root of 21266313 is about 4611.5412824781. The cubic root of 21266313 is about 277.0537719205.

The spelling of 21266313 in words is "twenty-one million, two hundred sixty-six thousand, three hundred thirteen".