21223842 has 8 divisors (see below), whose sum is σ = 42447696. Its totient is φ = 7074612.

The previous prime is 21223841. The next prime is 21223843. The reversal of 21223842 is 24832212.

It is an interprime number because it is at equal distance from previous prime (21223841) and next prime (21223843).

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

21223842 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (21223841) 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, 1768648 + ... + 1768659.

It is an arithmetic number, because the mean of its divisors is an integer number (5305962).

Almost surely, 2^21223842 is an apocalyptic number.

21223842 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21223842 is a wasteful number, since it uses less digits than its factorization.

21223842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3537312.

The product of its digits is 1536, while the sum is 24.

The square root of 21223842 is about 4606.9341215173. The cubic root of 21223842 is about 276.8692141086.

The spelling of 21223842 in words is "twenty-one million, two hundred twenty-three thousand, eight hundred forty-two".