21867871 has 8 divisors (see below), whose sum is σ = 22888800. Its totient is φ = 20852832.

The previous prime is 21867869. The next prime is 21867913. The reversal of 21867871 is 17876812.

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 21867871 - 2¹ = 21867869 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 (21867821) 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, 7305 + ... + 9853.

It is an arithmetic number, because the mean of its divisors is an integer number (2861100).

Almost surely, 2^21867871 is an apocalyptic number.

21867871 is a deficient number, since it is larger than the sum of its proper divisors (1020929).

21867871 is a wasteful number, since it uses less digits than its factorization.

21867871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2945.

The product of its digits is 37632, while the sum is 40.

The square root of 21867871 is about 4676.3095492065. The cubic root of 21867871 is about 279.6418507585.

The spelling of 21867871 in words is "twenty-one million, eight hundred sixty-seven thousand, eight hundred seventy-one".