21893867 has 4 divisors (see below), whose sum is σ = 22025136. Its totient is φ = 21762600.

The previous prime is 21893831. The next prime is 21893887. The reversal of 21893867 is 76839812.

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 21893867 - 2¹⁴ = 21877483 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21893827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65384 + ... + 65717.

It is an arithmetic number, because the mean of its divisors is an integer number (5506284).

Almost surely, 2^21893867 is an apocalyptic number.

21893867 is a deficient number, since it is larger than the sum of its proper divisors (131269).

21893867 is a wasteful number, since it uses less digits than its factorization.

21893867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131268.

The product of its digits is 145152, while the sum is 44.

The square root of 21893867 is about 4679.0882658911. The cubic root of 21893867 is about 279.7526173839.

The spelling of 21893867 in words is "twenty-one million, eight hundred ninety-three thousand, eight hundred sixty-seven".