21745564260213 has 4 divisors (see below), whose sum is σ = 28994085680288. Its totient is φ = 14497042840140.

The previous prime is 21745564260193. The next prime is 21745564260221. The reversal of 21745564260213 is 31206246554712.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21745564260213 - 2¹³ = 21745564252021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21745564260313) 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, 3624260710033 + ... + 3624260710038.

It is an arithmetic number, because the mean of its divisors is an integer number (7248521420072).

Almost surely, 2^{21745564260213} is an apocalyptic number.

It is an amenable number.

21745564260213 is a deficient number, since it is larger than the sum of its proper divisors (7248521420075).

21745564260213 is an equidigital number, since it uses as much as digits as its factorization.

21745564260213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7248521420074.

The product of its (nonzero) digits is 2419200, while the sum is 48.

The spelling of 21745564260213 in words is "twenty-one trillion, seven hundred forty-five billion, five hundred sixty-four million, two hundred sixty thousand, two hundred thirteen".