21138266075816 has 16 divisors (see below), whose sum is σ = 39683119741440. Its totient is φ = 10556100811440.

The previous prime is 21138266075743. The next prime is 21138266075851. The reversal of 21138266075816 is 61857066283112.

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, 1629021416 + ... + 1629034391.

It is an arithmetic number, because the mean of its divisors is an integer number (2480194983840).

Almost surely, 2^{21138266075816} is an apocalyptic number.

It is an amenable number.

21138266075816 is a deficient number, since it is larger than the sum of its proper divisors (18544853665624).

21138266075816 is a wasteful number, since it uses less digits than its factorization.

21138266075816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3258056624 (or 3258056620 counting only the distinct ones).

The product of its (nonzero) digits is 5806080, while the sum is 56.

The spelling of 21138266075816 in words is "twenty-one trillion, one hundred thirty-eight billion, two hundred sixty-six million, seventy-five thousand, eight hundred sixteen".