21540410304211 has 4 divisors (see below), whose sum is σ = 21578266913400. Its totient is φ = 21502553695024.

The previous prime is 21540410304197. The next prime is 21540410304299. The reversal of 21540410304211 is 11240301404512.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21540410304211 - 2¹³ = 21540410296019 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21540410304211.

It is not an unprimeable number, because it can be changed into a prime (21540410301211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18928303741 + ... + 18928304878.

It is an arithmetic number, because the mean of its divisors is an integer number (5394566728350).

Almost surely, 2^{21540410304211} is an apocalyptic number.

21540410304211 is a deficient number, since it is larger than the sum of its proper divisors (37856609189).

21540410304211 is an equidigital number, since it uses as much as digits as its factorization.

21540410304211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37856609188.

The product of its (nonzero) digits is 3840, while the sum is 28.

Adding to 21540410304211 its reverse (11240301404512), we get a palindrome (32780711708723).

The spelling of 21540410304211 in words is "twenty-one trillion, five hundred forty billion, four hundred ten million, three hundred four thousand, two hundred eleven".