21117307 has 8 divisors (see below), whose sum is σ = 21934800. Its totient is φ = 20305824.

The previous prime is 21117277. The next prime is 21117311. The reversal of 21117307 is 70371112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21117307 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21117347) 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, 6448 + ... + 9154.

It is an arithmetic number, because the mean of its divisors is an integer number (2741850).

Almost surely, 2^21117307 is an apocalyptic number.

21117307 is a deficient number, since it is larger than the sum of its proper divisors (817493).

21117307 is a wasteful number, since it uses less digits than its factorization.

21117307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3005.

The product of its (nonzero) digits is 294, while the sum is 22.

The square root of 21117307 is about 4595.3571134353. The cubic root of 21117307 is about 276.4051801090.

Adding to 21117307 its reverse (70371112), we get a palindrome (91488419).

The spelling of 21117307 in words is "twenty-one million, one hundred seventeen thousand, three hundred seven".