21210105404 has 48 divisors (see below), whose sum is σ = 39788050176. Its totient is φ = 9876672000.

The previous prime is 21210105383. The next prime is 21210105421. The reversal of 21210105404 is 40450101212.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 288629 + ... + 354579.

It is an arithmetic number, because the mean of its divisors is an integer number (828917712).

Almost surely, 2^21210105404 is an apocalyptic number.

It is an amenable number.

21210105404 is a deficient number, since it is larger than the sum of its proper divisors (18577944772).

21210105404 is a wasteful number, since it uses less digits than its factorization.

21210105404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66086 (or 66084 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

Adding to 21210105404 its reverse (40450101212), we get a palindrome (61660206616).

The spelling of 21210105404 in words is "twenty-one billion, two hundred ten million, one hundred five thousand, four hundred four".