22001000 has 96 divisors (see below), whose sum is σ = 60021000. Its totient is φ = 7526400.

The previous prime is 22000963. The next prime is 22001033. The reversal of 22001000 is 10022.

It can be written as a sum of positive squares in 4 ways, for example, as 7606564 + 14394436 = 2758^2 + 3794^2 .

It is a Harshad number since it is a multiple of its sum of digits (5).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 48776 + ... + 49224.

Almost surely, 2^22001000 is an apocalyptic number.

22001000 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 22001000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30010500).

22001000 is an abundant number, since it is smaller than the sum of its proper divisors (38020000).

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

22001000 is a wasteful number, since it uses less digits than its factorization.

22001000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 484 (or 463 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 5.

The square root of 22001000 is about 4690.5223589703. The cubic root of 22001000 is about 280.2081785154.

Adding to 22001000 its reverse (10022), we get a palindrome (22011022).

It can be divided in two parts, 2 and 2001000, that added together give a palindrome (2001002).

The spelling of 22001000 in words is "twenty-two million, one thousand".