21004167 has 8 divisors (see below), whose sum is σ = 28657024. Its totient is φ = 13677048.

The previous prime is 21004157. The next prime is 21004169. The reversal of 21004167 is 76140012.

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

It is not a de Polignac number, because 21004167 - 2¹⁴ = 20987783 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21004169) 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, 81283 + ... + 81540.

It is an arithmetic number, because the mean of its divisors is an integer number (3582128).

Almost surely, 2^21004167 is an apocalyptic number.

21004167 is a deficient number, since it is larger than the sum of its proper divisors (7652857).

21004167 is a wasteful number, since it uses less digits than its factorization.

21004167 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162869.

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 21004167 is about 4583.0303293782. The cubic root of 21004167 is about 275.9106647440.

Adding to 21004167 its reverse (76140012), we get a palindrome (97144179).

The spelling of 21004167 in words is "twenty-one million, four thousand, one hundred sixty-seven".