21187938068 has 12 divisors (see below), whose sum is σ = 40449700032. Its totient is φ = 9630880920.

The previous prime is 21187938043. The next prime is 21187938119. The reversal of 21187938068 is 86083978112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 240771980 + ... + 240772067.

It is an arithmetic number, because the mean of its divisors is an integer number (3370808336).

Almost surely, 2^21187938068 is an apocalyptic number.

It is an amenable number.

21187938068 is a deficient number, since it is larger than the sum of its proper divisors (19261761964).

21187938068 is a wasteful number, since it uses less digits than its factorization.

21187938068 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481544062 (or 481544060 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 53.

The spelling of 21187938068 in words is "twenty-one billion, one hundred eighty-seven million, nine hundred thirty-eight thousand, sixty-eight".