21012746684 has 24 divisors (see below), whose sum is σ = 38713948560. Its totient is φ = 9951797376.

The previous prime is 21012746683. The next prime is 21012746693. The reversal of 21012746684 is 48664721012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012746683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 545054 + ... + 582330.

It is an arithmetic number, because the mean of its divisors is an integer number (1613081190).

Almost surely, 2^21012746684 is an apocalyptic number.

It is an amenable number.

21012746684 is a deficient number, since it is larger than the sum of its proper divisors (17701201876).

21012746684 is a wasteful number, since it uses less digits than its factorization.

21012746684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44717 (or 44715 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 41.

The spelling of 21012746684 in words is "twenty-one billion, twelve million, seven hundred forty-six thousand, six hundred eighty-four".