22222820 has 36 divisors (see below), whose sum is σ = 47906292. Its totient is φ = 8659200.

The previous prime is 22222819. The next prime is 22222831. The reversal of 22222820 is 2822222.

It can be written as a sum of positive squares in 6 ways, for example, as 4700224 + 17522596 = 2168^2 + 4186^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 22222792 and 22222801.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 33290 + ... + 33950.

Almost surely, 2^22222820 is an apocalyptic number.

22222820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 22222820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23953146).

22222820 is an abundant number, since it is smaller than the sum of its proper divisors (25683472).

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

22222820 is a wasteful number, since it uses less digits than its factorization.

22222820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 752 (or 709 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 22222820 is about 4714.1086113920. The cubic root of 22222820 is about 281.1467426712.

The spelling of 22222820 in words is "twenty-two million, two hundred twenty-two thousand, eight hundred twenty".