21040020304 has 20 divisors (see below), whose sum is σ = 40912214164. Its totient is φ = 10482029568.

The previous prime is 21040020283. The next prime is 21040020311. The reversal of 21040020304 is 40302004012.

It can be written as a sum of positive squares in 2 ways, for example, as 13890979600 + 7149040704 = 117860^2 + 84552^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2369217 + ... + 2378080.

Almost surely, 2^21040020304 is an apocalyptic number.

It is an amenable number.

21040020304 is a deficient number, since it is larger than the sum of its proper divisors (19872193860).

21040020304 is a wasteful number, since it uses less digits than its factorization.

21040020304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4747582 (or 4747576 counting only the distinct ones).

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

Adding to 21040020304 its reverse (40302004012), we get a palindrome (61342024316).

The spelling of 21040020304 in words is "twenty-one billion, forty million, twenty thousand, three hundred four".