21375167 has 4 divisors (see below), whose sum is σ = 23318376. Its totient is φ = 19431960.

The previous prime is 21375163. The next prime is 21375173. The reversal of 21375167 is 76157312.

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 21375167 - 2² = 21375163 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 (21375163) 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, 971588 + ... + 971609.

It is an arithmetic number, because the mean of its divisors is an integer number (5829594).

Almost surely, 2^21375167 is an apocalyptic number.

21375167 is a deficient number, since it is larger than the sum of its proper divisors (1943209).

21375167 is a wasteful number, since it uses less digits than its factorization.

21375167 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1943208.

The product of its digits is 8820, while the sum is 32.

The square root of 21375167 is about 4623.3285628430. The cubic root of 21375167 is about 277.5256778987.

The spelling of 21375167 in words is "twenty-one million, three hundred seventy-five thousand, one hundred sixty-seven".