21004775530 has 24 divisors (see below), whose sum is σ = 39523929732. Its totient is φ = 8036607744.

The previous prime is 21004775521. The next prime is 21004775531. The reversal of 21004775530 is 3557740012.

It can be written as a sum of positive squares in 2 ways, for example, as 21002675929 + 2099601 = 144923^2 + 1449^2 .

It is not an unprimeable number, because it can be changed into a prime (21004775531) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1980039 + ... + 1990618.

Almost surely, 2^21004775530 is an apocalyptic number.

21004775530 is a deficient number, since it is larger than the sum of its proper divisors (18519154202).

21004775530 is a wasteful number, since it uses less digits than its factorization.

21004775530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3970710 (or 3970687 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 34.

The spelling of 21004775530 in words is "twenty-one billion, four million, seven hundred seventy-five thousand, five hundred thirty".