21220320004 has 12 divisors (see below), whose sum is σ = 39992141644. Its totient is φ = 9793993824.

The previous prime is 21220320001. The next prime is 21220320049. The reversal of 21220320004 is 40002302212.

It can be written as a sum of positive squares in 2 ways, for example, as 12187718404 + 9032601600 = 110398^2 + 95040^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21220320004.

It is not an unprimeable number, because it can be changed into a prime (21220320001) 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, 204041487 + ... + 204041590.

Almost surely, 2^21220320004 is an apocalyptic number.

It is an amenable number.

21220320004 is a deficient number, since it is larger than the sum of its proper divisors (18771821640).

21220320004 is a wasteful number, since it uses less digits than its factorization.

21220320004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408083094 (or 408083092 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

Adding to 21220320004 its reverse (40002302212), we get a palindrome (61222622216).

The spelling of 21220320004 in words is "twenty-one billion, two hundred twenty million, three hundred twenty thousand, four".