21112307 has 4 divisors (see below), whose sum is σ = 21238896. Its totient is φ = 20985720.

The previous prime is 21112291. The next prime is 21112339. The reversal of 21112307 is 70321112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21112307 - 2⁴ = 21112291 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21112207) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63044 + ... + 63377.

It is an arithmetic number, because the mean of its divisors is an integer number (5309724).

Almost surely, 2^21112307 is an apocalyptic number.

21112307 is a deficient number, since it is larger than the sum of its proper divisors (126589).

21112307 is a wasteful number, since it uses less digits than its factorization.

21112307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126588.

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 21112307 is about 4594.8130538685. The cubic root of 21112307 is about 276.3833633280.

Adding to 21112307 its reverse (70321112), we get a palindrome (91433419).

The spelling of 21112307 in words is "twenty-one million, one hundred twelve thousand, three hundred seven".