21213104684 has 24 divisors (see below), whose sum is σ = 37349037600. Its totient is φ = 10542064896.

The previous prime is 21213104681. The next prime is 21213104729. The reversal of 21213104684 is 48640131212.

It is a self number, because there is not a number n which added to its sum of digits gives 21213104684.

It is not an unprimeable number, because it can be changed into a prime (21213104681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 764054 + ... + 791330.

It is an arithmetic number, because the mean of its divisors is an integer number (1556209900).

Almost surely, 2^21213104684 is an apocalyptic number.

It is an amenable number.

21213104684 is a deficient number, since it is larger than the sum of its proper divisors (16135932916).

21213104684 is a wasteful number, since it uses less digits than its factorization.

21213104684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28457 (or 28455 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

Adding to 21213104684 its reverse (48640131212), we get a palindrome (69853235896).

The spelling of 21213104684 in words is "twenty-one billion, two hundred thirteen million, one hundred four thousand, six hundred eighty-four".