21857017223493 has 12 divisors (see below), whose sum is σ = 31896723876108. Its totient is φ = 14421124765440.

The previous prime is 21857017223477. The next prime is 21857017223519. The reversal of 21857017223493 is 39432271075812.

21857017223493 is a `hidden beast` number, since 2 + 1 + 8 + 570 + 1 + 7 + 2 + 23 + 49 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 11747879640324 + 10109137583169 = 3427518^2 + 3179487^2 .

It is not a de Polignac number, because 21857017223493 - 2⁴ = 21857017223477 is a prime.

It is a super-2 number, since 2×21857017223493² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21857017223593) 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, 12518336598 + ... + 12518338343.

It is an arithmetic number, because the mean of its divisors is an integer number (2658060323009).

Almost surely, 2^{21857017223493} is an apocalyptic number.

It is an amenable number.

21857017223493 is a deficient number, since it is larger than the sum of its proper divisors (10039706652615).

21857017223493 is a wasteful number, since it uses less digits than its factorization.

21857017223493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25036675044 (or 25036675041 counting only the distinct ones).

The product of its (nonzero) digits is 5080320, while the sum is 54.

The spelling of 21857017223493 in words is "twenty-one trillion, eight hundred fifty-seven billion, seventeen million, two hundred twenty-three thousand, four hundred ninety-three".