21267847 has 8 divisors (see below), whose sum is σ = 22270176. Its totient is φ = 20272032.

The previous prime is 21267839. The next prime is 21267853. The reversal of 21267847 is 74876212.

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

It is a cyclic number.

It is not a de Polignac number, because 21267847 - 2³ = 21267839 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 (21267887) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5833 + ... + 8749.

It is an arithmetic number, because the mean of its divisors is an integer number (2783772).

Almost surely, 2^21267847 is an apocalyptic number.

21267847 is the 2917-th heptagonal number.

21267847 is a deficient number, since it is larger than the sum of its proper divisors (1002329).

21267847 is a wasteful number, since it uses less digits than its factorization.

21267847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3257.

The product of its digits is 37632, while the sum is 37.

The square root of 21267847 is about 4611.7076013121. The cubic root of 21267847 is about 277.0604333208.

The spelling of 21267847 in words is "twenty-one million, two hundred sixty-seven thousand, eight hundred forty-seven".