21916873 has 16 divisors (see below), whose sum is σ = 24641280. Its totient is φ = 19324800.

The previous prime is 21916871. The next prime is 21916877. The reversal of 21916873 is 37861912.

It is not a de Polignac number, because 21916873 - 2¹ = 21916871 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21916871) 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 15 ways as a sum of consecutive naturals, for example, 59536 + ... + 59902.

It is an arithmetic number, because the mean of its divisors is an integer number (1540080).

Almost surely, 2^21916873 is an apocalyptic number.

It is an amenable number.

21916873 is a deficient number, since it is larger than the sum of its proper divisors (2724407).

21916873 is a wasteful number, since it uses less digits than its factorization.

21916873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528.

The product of its digits is 18144, while the sum is 37.

The square root of 21916873 is about 4681.5460053277. The cubic root of 21916873 is about 279.8505707776.

The spelling of 21916873 in words is "twenty-one million, nine hundred sixteen thousand, eight hundred seventy-three".