21202667 has 4 divisors (see below), whose sum is σ = 21886656. Its totient is φ = 20518680.

The previous prime is 21202663. The next prime is 21202669. The reversal of 21202667 is 76620212.

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 21202667 - 2² = 21202663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21202663) 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 3 ways as a sum of consecutive naturals, for example, 341948 + ... + 342009.

It is an arithmetic number, because the mean of its divisors is an integer number (5471664).

Almost surely, 2^21202667 is an apocalyptic number.

21202667 is a deficient number, since it is larger than the sum of its proper divisors (683989).

21202667 is an equidigital number, since it uses as much as digits as its factorization.

21202667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 683988.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 21202667 is about 4604.6353818734. The cubic root of 21202667 is about 276.7771061163. Note that the first 3 decimals are identical.

Adding to 21202667 its reverse (76620212), we get a palindrome (97822879).

The spelling of 21202667 in words is "twenty-one million, two hundred two thousand, six hundred sixty-seven".