21713541745 has 24 divisors (see below), whose sum is σ = 30588445800. Its totient is φ = 14752668672.

The previous prime is 21713541727. The next prime is 21713541757. The reversal of 21713541745 is 54714531712.

It can be written as a sum of positive squares in 4 ways, for example, as 1008634081 + 20704907664 = 31759^2 + 143892^2 .

It is not a de Polignac number, because 21713541745 - 2⁷ = 21713541617 is a prime.

It is a super-2 number, since 2×21713541745² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21713541698 and 21713541707.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 379840 + ... + 433249.

It is an arithmetic number, because the mean of its divisors is an integer number (1274518575).

Almost surely, 2^21713541745 is an apocalyptic number.

It is an amenable number.

21713541745 is a deficient number, since it is larger than the sum of its proper divisors (8874904055).

21713541745 is a wasteful number, since it uses less digits than its factorization.

21713541745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 813217 (or 813210 counting only the distinct ones).

The product of its digits is 117600, while the sum is 40.

The spelling of 21713541745 in words is "twenty-one billion, seven hundred thirteen million, five hundred forty-one thousand, seven hundred forty-five".