21385075775 has 24 divisors (see below), whose sum is σ = 30318354144. Its totient is φ = 14657932800.

The previous prime is 21385075759. The next prime is 21385075783. The reversal of 21385075775 is 57757058312.

It is not a de Polignac number, because 21385075775 - 2⁴ = 21385075759 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 23 ways as a sum of consecutive naturals, for example, 416939 + ... + 465411.

It is an arithmetic number, because the mean of its divisors is an integer number (1263264756).

Almost surely, 2^21385075775 is an apocalyptic number.

21385075775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21385075775 is a deficient number, since it is larger than the sum of its proper divisors (8933278369).

21385075775 is a wasteful number, since it uses less digits than its factorization.

21385075775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51011 (or 51006 counting only the distinct ones).

The product of its (nonzero) digits is 2058000, while the sum is 50.

The spelling of 21385075775 in words is "twenty-one billion, three hundred eighty-five million, seventy-five thousand, seven hundred seventy-five".