21109938068 has 12 divisors (see below), whose sum is σ = 38886728160. Its totient is φ = 9999444312.

The previous prime is 21109938067. The next prime is 21109938097. The reversal of 21109938068 is 86083990112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21109938061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138881096 + ... + 138881247.

It is an arithmetic number, because the mean of its divisors is an integer number (3240560680).

Almost surely, 2^21109938068 is an apocalyptic number.

It is an amenable number.

21109938068 is a deficient number, since it is larger than the sum of its proper divisors (17776790092).

21109938068 is a wasteful number, since it uses less digits than its factorization.

21109938068 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277762366 (or 277762364 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 47.

The spelling of 21109938068 in words is "twenty-one billion, one hundred nine million, nine hundred thirty-eight thousand, sixty-eight".