21127168686 has 16 divisors (see below), whose sum is σ = 45504671184. Its totient is φ = 6500667264.

The previous prime is 21127168661. The next prime is 21127168717. The reversal of 21127168686 is 68686172112.

It is a Curzon number.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 135430491 + ... + 135430646.

It is an arithmetic number, because the mean of its divisors is an integer number (2844041949).

Almost surely, 2^21127168686 is an apocalyptic number.

21127168686 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21127168686 is an abundant number, since it is smaller than the sum of its proper divisors (24377502498).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21127168686 is a wasteful number, since it uses less digits than its factorization.

21127168686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270861155.

The product of its digits is 387072, while the sum is 48.

The spelling of 21127168686 in words is "twenty-one billion, one hundred twenty-seven million, one hundred sixty-eight thousand, six hundred eighty-six".