21866673 has 4 divisors (see below), whose sum is σ = 29155568. Its totient is φ = 14577780.

The previous prime is 21866671. The next prime is 21866693. The reversal of 21866673 is 37666812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21866673 - 2¹ = 21866671 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21866671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3644443 + ... + 3644448.

It is an arithmetic number, because the mean of its divisors is an integer number (7288892).

Almost surely, 2^21866673 is an apocalyptic number.

It is an amenable number.

21866673 is a deficient number, since it is larger than the sum of its proper divisors (7288895).

21866673 is an equidigital number, since it uses as much as digits as its factorization.

21866673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7288894.

The product of its digits is 72576, while the sum is 39.

The square root of 21866673 is about 4676.1814549908. The cubic root of 21866673 is about 279.6367440725.

The spelling of 21866673 in words is "twenty-one million, eight hundred sixty-six thousand, six hundred seventy-three".