22404021 has 24 divisors (see below), whose sum is σ = 31967424. Its totient is φ = 13953600.

The previous prime is 22403987. The next prime is 22404061. The reversal of 22404021 is 12040422.

It is a de Polignac number, because none of the positive numbers 2^k-22404021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22404061) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 148296 + ... + 148446.

It is an arithmetic number, because the mean of its divisors is an integer number (1331976).

Almost surely, 2^22404021 is an apocalyptic number.

It is an amenable number.

22404021 is a deficient number, since it is larger than the sum of its proper divisors (9563403).

22404021 is a wasteful number, since it uses less digits than its factorization.

22404021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329 (or 310 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 22404021 is about 4733.2886030750. The cubic root of 22404021 is about 281.9088156473.

Adding to 22404021 its reverse (12040422), we get a palindrome (34444443).

The spelling of 22404021 in words is "twenty-two million, four hundred four thousand, twenty-one".