21864273 has 8 divisors (see below), whose sum is σ = 29425248. Its totient is φ = 14439744.

The previous prime is 21864263. The next prime is 21864281. The reversal of 21864273 is 37246812.

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

It is not a de Polignac number, because 21864273 - 2⁶ = 21864209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21864263) 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, 33736 + ... + 34377.

It is an arithmetic number, because the mean of its divisors is an integer number (3678156).

Almost surely, 2^21864273 is an apocalyptic number.

It is an amenable number.

21864273 is a deficient number, since it is larger than the sum of its proper divisors (7560975).

21864273 is a wasteful number, since it uses less digits than its factorization.

21864273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68223.

The product of its digits is 16128, while the sum is 33.

The square root of 21864273 is about 4675.9248283094. The cubic root of 21864273 is about 279.6265130885.

The spelling of 21864273 in words is "twenty-one million, eight hundred sixty-four thousand, two hundred seventy-three".