22121021 has 4 divisors (see below), whose sum is σ = 23822652. Its totient is φ = 20419392.

The previous prime is 22121003. The next prime is 22121041. The reversal of 22121021 is 12012122.

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 10797796 + 11323225 = 3286^2 + 3365^2 .

It is a cyclic number.

It is not a de Polignac number, because 22121021 - 2⁶ = 22120957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22120993 and 22121011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22121041) 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, 850796 + ... + 850821.

It is an arithmetic number, because the mean of its divisors is an integer number (5955663).

Almost surely, 2^22121021 is an apocalyptic number.

It is an amenable number.

22121021 is a deficient number, since it is larger than the sum of its proper divisors (1701631).

22121021 is a wasteful number, since it uses less digits than its factorization.

22121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1701630.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 22121021 is about 4703.2989486104. The cubic root of 22121021 is about 280.7167901772.

Adding to 22121021 its reverse (12012122), we get a palindrome (34133143).

The spelling of 22121021 in words is "twenty-two million, one hundred twenty-one thousand, twenty-one".