21600667 has 16 divisors (see below), whose sum is σ = 24312960. Its totient is φ = 19024000.

The previous prime is 21600647. The next prime is 21600673. The reversal of 21600667 is 76600612.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21600667 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (21600617) 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 15 ways as a sum of consecutive naturals, for example, 53667 + ... + 54067.

It is an arithmetic number, because the mean of its divisors is an integer number (1519560).

Almost surely, 2^21600667 is an apocalyptic number.

21600667 is a deficient number, since it is larger than the sum of its proper divisors (2712293).

21600667 is a wasteful number, since it uses less digits than its factorization.

21600667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 21600667 is about 4647.6517726697. The cubic root of 21600667 is about 278.4981965981.

Subtracting 21600667 from its reverse (76600612), we obtain a palindrome (54999945).

The spelling of 21600667 in words is "twenty-one million, six hundred thousand, six hundred sixty-seven".