21207814 has 8 divisors (see below), whose sum is σ = 32247720. Its totient is φ = 10458576.

The previous prime is 21207811. The next prime is 21207839. The reversal of 21207814 is 41870212.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21207811) 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 3 ways as a sum of consecutive naturals, for example, 72484 + ... + 72775.

It is an arithmetic number, because the mean of its divisors is an integer number (4030965).

Almost surely, 2^21207814 is an apocalyptic number.

21207814 is a deficient number, since it is larger than the sum of its proper divisors (11039906).

21207814 is a wasteful number, since it uses less digits than its factorization.

21207814 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145334.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 21207814 is about 4605.1942412889. The cubic root of 21207814 is about 276.7995004140.

The spelling of 21207814 in words is "twenty-one million, two hundred seven thousand, eight hundred fourteen".