21785078938075 has 12 divisors (see below), whose sum is σ = 27013662363168. Its totient is φ = 17427957034400.

The previous prime is 21785078938061. The next prime is 21785078938079. The reversal of 21785078938075 is 57083987058712.

It is not a de Polignac number, because 21785078938075 - 2³³ = 21776489003483 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21785078937995 and 21785078938013.

It is not an unprimeable number, because it can be changed into a prime (21785078938079) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1673454 + ... + 6809596.

It is an arithmetic number, because the mean of its divisors is an integer number (2251138530264).

Almost surely, 2^{21785078938075} is an apocalyptic number.

21785078938075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21785078938075 is a deficient number, since it is larger than the sum of its proper divisors (5228583425093).

21785078938075 is a wasteful number, since it uses less digits than its factorization.

21785078938075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5305814 (or 5305809 counting only the distinct ones).

The product of its (nonzero) digits is 237081600, while the sum is 70.

The spelling of 21785078938075 in words is "twenty-one trillion, seven hundred eighty-five billion, seventy-eight million, nine hundred thirty-eight thousand, seventy-five".