21367147 has 4 divisors (see below), whose sum is σ = 22624056. Its totient is φ = 20110240.

The previous prime is 21367139. The next prime is 21367163. The reversal of 21367147 is 74176312.

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 21367147 - 2³ = 21367139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21367127) 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, 628429 + ... + 628462.

It is an arithmetic number, because the mean of its divisors is an integer number (5656014).

Almost surely, 2^21367147 is an apocalyptic number.

21367147 is a deficient number, since it is larger than the sum of its proper divisors (1256909).

21367147 is a wasteful number, since it uses less digits than its factorization.

21367147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1256908.

The product of its digits is 7056, while the sum is 31.

The square root of 21367147 is about 4622.4611409940. The cubic root of 21367147 is about 277.4909641838.

The spelling of 21367147 in words is "twenty-one million, three hundred sixty-seven thousand, one hundred forty-seven".