22040021 has 4 divisors (see below), whose sum is σ = 22154412. Its totient is φ = 21925632.

The previous prime is 22040009. The next prime is 22040023. The reversal of 22040021 is 12004022.

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 10817521 + 11222500 = 3289^2 + 3350^2 .

It is a cyclic number.

It is not a de Polignac number, because 22040021 - 2²² = 17845717 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22039984 and 22040011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22040023) 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, 56906 + ... + 57291.

It is an arithmetic number, because the mean of its divisors is an integer number (5538603).

Almost surely, 2^22040021 is an apocalyptic number.

It is an amenable number.

22040021 is a deficient number, since it is larger than the sum of its proper divisors (114391).

22040021 is a wasteful number, since it uses less digits than its factorization.

22040021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114390.

The product of its (nonzero) digits is 32, while the sum is 11.

The square root of 22040021 is about 4694.6800742969. The cubic root of 22040021 is about 280.3737398612.

Adding to 22040021 its reverse (12004022), we get a palindrome (34044043).

The spelling of 22040021 in words is "twenty-two million, forty thousand, twenty-one".