21138318126775 has 12 divisors (see below), whose sum is σ = 26238620520112. Its totient is φ = 16893166731840.

The previous prime is 21138318126769. The next prime is 21138318126787. The reversal of 21138318126775 is 57762181383112.

It is not a de Polignac number, because 21138318126775 - 2⁷ = 21138318126647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 437169582 + ... + 437217931.

Almost surely, 2^{21138318126775} is an apocalyptic number.

21138318126775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21138318126775 is a deficient number, since it is larger than the sum of its proper divisors (5100302393337).

21138318126775 is an equidigital number, since it uses as much as digits as its factorization.

21138318126775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 874388490 (or 874388485 counting only the distinct ones).

The product of its digits is 3386880, while the sum is 55.

The spelling of 21138318126775 in words is "twenty-one trillion, one hundred thirty-eight billion, three hundred eighteen million, one hundred twenty-six thousand, seven hundred seventy-five".