22018121 has 4 divisors (see below), whose sum is σ = 22114500. Its totient is φ = 21921744.

The previous prime is 22018103. The next prime is 22018123. The reversal of 22018121 is 12181022.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21492496 + 525625 = 4636^2 + 725^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22018121 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 22018121.

It is not an unprimeable number, because it can be changed into a prime (22018123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47846 + ... + 48303.

It is an arithmetic number, because the mean of its divisors is an integer number (5528625).

Almost surely, 2^22018121 is an apocalyptic number.

It is an amenable number.

22018121 is a deficient number, since it is larger than the sum of its proper divisors (96379).

22018121 is an equidigital number, since it uses as much as digits as its factorization.

22018121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96378.

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 22018121 is about 4692.3470673001. The cubic root of 22018121 is about 280.2808449141.

Adding to 22018121 its reverse (12181022), we get a palindrome (34199143).

The spelling of 22018121 in words is "twenty-two million, eighteen thousand, one hundred twenty-one".