21031228648 has 16 divisors (see below), whose sum is σ = 39988956960. Its totient is φ = 10367506800.

The previous prime is 21031228637. The next prime is 21031228693. The reversal of 21031228648 is 84682213012.

It is a happy number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 18512838 + ... + 18513973.

It is an arithmetic number, because the mean of its divisors is an integer number (2499309810).

Almost surely, 2^21031228648 is an apocalyptic number.

It is an amenable number.

21031228648 is a deficient number, since it is larger than the sum of its proper divisors (18957728312).

21031228648 is a wasteful number, since it uses less digits than its factorization.

21031228648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37026888 (or 37026884 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 37.

The spelling of 21031228648 in words is "twenty-one billion, thirty-one million, two hundred twenty-eight thousand, six hundred forty-eight".