21004422 has 16 divisors (see below), whose sum is σ = 43364352. Its totient is φ = 6775560.

The previous prime is 21004387. The next prime is 21004447. The reversal of 21004422 is 22440012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56278 + ... + 56649.

It is an arithmetic number, because the mean of its divisors is an integer number (2710272).

Almost surely, 2^21004422 is an apocalyptic number.

21004422 is an abundant number, since it is smaller than the sum of its proper divisors (22359930).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21004422 is a wasteful number, since it uses less digits than its factorization.

21004422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112963.

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

The square root of 21004422 is about 4583.0581493147. The cubic root of 21004422 is about 275.9117812992.

Adding to 21004422 its reverse (22440012), we get a palindrome (43444434).

It can be divided in two parts, 21004 and 422, that multiplied together give a palindrome (8863688).

The spelling of 21004422 in words is "twenty-one million, four thousand, four hundred twenty-two".