22402021 has 4 divisors (see below), whose sum is σ = 22708972. Its totient is φ = 22095072.

The previous prime is 22402013. The next prime is 22402049. The reversal of 22402021 is 12020422.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12020422 = 2 ⋅6010211.

It can be written as a sum of positive squares in 2 ways, for example, as 17388900 + 5013121 = 4170^2 + 2239^2 .

It is a cyclic number.

It is not a de Polignac number, because 22402021 - 2³ = 22402013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22401992 and 22402010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22402091) 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, 153366 + ... + 153511.

It is an arithmetic number, because the mean of its divisors is an integer number (5677243).

Almost surely, 2^22402021 is an apocalyptic number.

It is an amenable number.

22402021 is a deficient number, since it is larger than the sum of its proper divisors (306951).

22402021 is an equidigital number, since it uses as much as digits as its factorization.

22402021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306950.

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 22402021 is about 4733.0773287577. The cubic root of 22402021 is about 281.9004267602.

Adding to 22402021 its reverse (12020422), we get a palindrome (34422443).

The spelling of 22402021 in words is "twenty-two million, four hundred two thousand, twenty-one".