21013660684 has 6 divisors (see below), whose sum is σ = 36773906204. Its totient is φ = 10506830340.

The previous prime is 21013660667. The next prime is 21013660691. The reversal of 21013660684 is 48606631012.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2626707582 + ... + 2626707589.

Almost surely, 2^21013660684 is an apocalyptic number.

It is an amenable number.

21013660684 is a deficient number, since it is larger than the sum of its proper divisors (15760245520).

21013660684 is a wasteful number, since it uses less digits than its factorization.

21013660684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5253415175 (or 5253415173 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 37.

The spelling of 21013660684 in words is "twenty-one billion, thirteen million, six hundred sixty thousand, six hundred eighty-four".