21890222 has 4 divisors (see below), whose sum is σ = 32835336. Its totient is φ = 10945110.

The previous prime is 21890221. The next prime is 21890243. The reversal of 21890222 is 22209812.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 21890191 and 21890200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21890221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5472554 + ... + 5472557.

It is an arithmetic number, because the mean of its divisors is an integer number (8208834).

Almost surely, 2^21890222 is an apocalyptic number.

21890222 is a deficient number, since it is larger than the sum of its proper divisors (10945114).

21890222 is a wasteful number, since it uses less digits than its factorization.

21890222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10945113.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 21890222 is about 4678.6987507212. The cubic root of 21890222 is about 279.7370916526.

The spelling of 21890222 in words is "twenty-one million, eight hundred ninety thousand, two hundred twenty-two".