22021000 has 96 divisors (see below), whose sum is σ = 55275480. Its totient is φ = 8208000.

The previous prime is 22020991. The next prime is 22021007. The reversal of 22021000 is 12022.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1572516 + 20448484 = 1254^2 + 4522^2 .

It is not an unprimeable number, because it can be changed into a prime (22021007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 360970 + ... + 361030.

Almost surely, 2^22021000 is an apocalyptic number.

22021000 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 22021000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27637740).

22021000 is an abundant number, since it is smaller than the sum of its proper divisors (33254480).

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

22021000 is a wasteful number, since it uses less digits than its factorization.

22021000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120 (or 87 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 7.

The square root of 22021000 is about 4692.6538333868. The cubic root of 22021000 is about 280.2930605097.

Adding to 22021000 its reverse (12022), we get a palindrome (22033022).

The spelling of 22021000 in words is "twenty-two million, twenty-one thousand".