21355684012 has 24 divisors (see below), whose sum is σ = 40270538672. Its totient is φ = 9850766400.

The previous prime is 21355684001. The next prime is 21355684033. The reversal of 21355684012 is 21048655312.

It is a super-2 number, since 2×21355684012² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27414 + ... + 208477.

Almost surely, 2^21355684012 is an apocalyptic number.

It is an amenable number.

21355684012 is a deficient number, since it is larger than the sum of its proper divisors (18914854660).

21355684012 is a wasteful number, since it uses less digits than its factorization.

21355684012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237649 (or 237647 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 37.

The spelling of 21355684012 in words is "twenty-one billion, three hundred fifty-five million, six hundred eighty-four thousand, twelve".