21105688245 has 16 divisors (see below), whose sum is σ = 33774214272. Its totient is φ = 11254662720.

The previous prime is 21105688217. The next prime is 21105688271. The reversal of 21105688245 is 54288650112.

It is not a de Polignac number, because 21105688245 - 2²⁴ = 21088911029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21105688197 and 21105688206.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 766 + ... + 205455.

It is an arithmetic number, because the mean of its divisors is an integer number (2110888392).

Almost surely, 2^21105688245 is an apocalyptic number.

It is an amenable number.

21105688245 is a deficient number, since it is larger than the sum of its proper divisors (12668526027).

21105688245 is a wasteful number, since it uses less digits than its factorization.

21105688245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213052.

The product of its (nonzero) digits is 153600, while the sum is 42.

The spelling of 21105688245 in words is "twenty-one billion, one hundred five million, six hundred eighty-eight thousand, two hundred forty-five".