22221810 has 96 divisors (see below), whose sum is σ = 64298880. Its totient is φ = 5458752.

The previous prime is 22221799. The next prime is 22221817. The reversal of 22221810 is 1812222.

It is a happy number.

It is a super-2 number, since 2×22221810² = 987617679352200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22221817) 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 47 ways as a sum of consecutive naturals, for example, 45387 + ... + 45873.

It is an arithmetic number, because the mean of its divisors is an integer number (669780).

Almost surely, 2^22221810 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 22221810, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32149440).

22221810 is an abundant number, since it is smaller than the sum of its proper divisors (42077070).

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

22221810 is a wasteful number, since it uses less digits than its factorization.

22221810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 529 (or 510 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 22221810 is about 4714.0014849382. The cubic root of 22221810 is about 281.1424833481.

The spelling of 22221810 in words is "twenty-two million, two hundred twenty-one thousand, eight hundred ten".