22001 has 6 divisors (see below), whose sum is σ = 25650. Its totient is φ = 18816.

The previous prime is 21997. The next prime is 22003. The reversal of 22001 is 10022.

It can be written as a sum of positive squares in only one way, i.e., 19600 + 2401 = 140^2 + 49^2 .

It is not a de Polignac number, because 22001 - 2² = 21997 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (22003) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 176 + ... + 273.

It is an arithmetic number, because the mean of its divisors is an integer number (4275).

2²²⁰⁰¹ is an apocalyptic number.

It is an amenable number.

22001 is a deficient number, since it is larger than the sum of its proper divisors (3649).

22001 is an equidigital number, since it uses as much as digits as its factorization.

22001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 463 (or 456 counting only the distinct ones).

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

The square root of 22001 is about 148.3273407029. The cubic root of 22001 is about 28.0208178515.

Adding to 22001 its reverse (10022), we get a palindrome (32023).

Multiplying 22001 by its reverse (10022), we get a palindrome (220494022).

The spelling of 22001 in words is "twenty-two thousand, one", and thus it is an iban number.