21275317 has 8 divisors (see below), whose sum is σ = 24501312. Its totient is φ = 18096000.

The previous prime is 21275311. The next prime is 21275321. The reversal of 21275317 is 71357212.

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 21275317 - 2¹⁵ = 21242549 is a prime.

It is a super-2 number, since 2×21275317² = 905278226900978, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21275311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10684 + ... + 12517.

It is an arithmetic number, because the mean of its divisors is an integer number (3062664).

Almost surely, 2^21275317 is an apocalyptic number.

It is an amenable number.

21275317 is a deficient number, since it is larger than the sum of its proper divisors (3225995).

21275317 is a wasteful number, since it uses less digits than its factorization.

21275317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23339.

The product of its digits is 2940, while the sum is 28.

The square root of 21275317 is about 4612.5174254413. The cubic root of 21275317 is about 277.0928672444.

The spelling of 21275317 in words is "twenty-one million, two hundred seventy-five thousand, three hundred seventeen".