21856222 has 8 divisors (see below), whose sum is σ = 33482016. Its totient is φ = 10695552.

The previous prime is 21856217. The next prime is 21856229. The reversal of 21856222 is 22265812.

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

It is a super-2 number, since 2×21856222² = 955388880226568, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21856229) 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, 116163 + ... + 116350.

It is an arithmetic number, because the mean of its divisors is an integer number (4185252).

Almost surely, 2^21856222 is an apocalyptic number.

21856222 is a deficient number, since it is larger than the sum of its proper divisors (11625794).

21856222 is a wasteful number, since it uses less digits than its factorization.

21856222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232562.

The product of its digits is 3840, while the sum is 28.

The square root of 21856222 is about 4675.0638498314. The cubic root of 21856222 is about 279.5921869310.

The spelling of 21856222 in words is "twenty-one million, eight hundred fifty-six thousand, two hundred twenty-two".