21001209304 has 8 divisors (see below), whose sum is σ = 39377267460. Its totient is φ = 10500604648.

The previous prime is 21001209269. The next prime is 21001209329. The reversal of 21001209304 is 40390210012.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1312575574 + ... + 1312575589.

Almost surely, 2^21001209304 is an apocalyptic number.

It is an amenable number.

21001209304 is a deficient number, since it is larger than the sum of its proper divisors (18376058156).

21001209304 is a wasteful number, since it uses less digits than its factorization.

21001209304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2625151169 (or 2625151165 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 21001209304 its reverse (40390210012), we get a palindrome (61391419316).

The spelling of 21001209304 in words is "twenty-one billion, one million, two hundred nine thousand, three hundred four".