21018075785 has 32 divisors (see below), whose sum is σ = 30371500800. Its totient is φ = 13640520960.

The previous prime is 21018075773. The next prime is 21018075791. The reversal of 21018075785 is 58757081012.

It is not a de Polignac number, because 21018075785 - 2⁴ = 21018075769 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 690671 + ... + 720459.

It is an arithmetic number, because the mean of its divisors is an integer number (949109400).

Almost surely, 2^21018075785 is an apocalyptic number.

It is an amenable number.

21018075785 is a deficient number, since it is larger than the sum of its proper divisors (9353425015).

21018075785 is a wasteful number, since it uses less digits than its factorization.

21018075785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30881.

The product of its (nonzero) digits is 156800, while the sum is 44.

The spelling of 21018075785 in words is "twenty-one billion, eighteen million, seventy-five thousand, seven hundred eighty-five".