20221000 has 64 divisors (see below), whose sum is σ = 48138480. Its totient is φ = 7948800.

The previous prime is 20220983. The next prime is 20221009. The reversal of 20221000 is 12202.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 24964 + 20196036 = 158^2 + 4494^2 .

It is not an unprimeable number, because it can be changed into a prime (20221009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72862 + ... + 73138.

Almost surely, 2^20221000 is an apocalyptic number.

20221000 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 20221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24069240).

20221000 is an abundant number, since it is smaller than the sum of its proper divisors (27917480).

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

20221000 is a wasteful number, since it uses less digits than its factorization.

20221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371 (or 357 counting only the distinct ones).

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

The square root of 20221000 is about 4496.7766233159. The cubic root of 20221000 is about 272.4379119551.

Adding to 20221000 its reverse (12202), we get a palindrome (20233202).

The spelling of 20221000 in words is "twenty million, two hundred twenty-one thousand".