21140540345 has 4 divisors (see below), whose sum is σ = 25368648420. Its totient is φ = 16912432272.

The previous prime is 21140540327. The next prime is 21140540359. The reversal of 21140540345 is 54304504112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12431358016 + 8709182329 = 111496^2 + 93323^2 .

It is a cyclic number.

It is not a de Polignac number, because 21140540345 - 2¹⁶ = 21140474809 is a prime.

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 3 ways as a sum of consecutive naturals, for example, 2114054030 + ... + 2114054039.

It is an arithmetic number, because the mean of its divisors is an integer number (6342162105).

Almost surely, 2^21140540345 is an apocalyptic number.

It is an amenable number.

21140540345 is a deficient number, since it is larger than the sum of its proper divisors (4228108075).

21140540345 is an equidigital number, since it uses as much as digits as its factorization.

21140540345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4228108074.

The product of its (nonzero) digits is 9600, while the sum is 29.

The spelling of 21140540345 in words is "twenty-one billion, one hundred forty million, five hundred forty thousand, three hundred forty-five".