21166304354213 has 4 divisors (see below), whose sum is σ = 21421320069408. Its totient is φ = 20911288639020.

The previous prime is 21166304354201. The next prime is 21166304354219. The reversal of 21166304354213 is 31245340366112.

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 a cyclic number.

It is not a de Polignac number, because 21166304354213 - 2⁴⁰ = 20066792726437 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 (21166304354219) 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, 127507857473 + ... + 127507857638.

It is an arithmetic number, because the mean of its divisors is an integer number (5355330017352).

Almost surely, 2^{21166304354213} is an apocalyptic number.

It is an amenable number.

21166304354213 is a deficient number, since it is larger than the sum of its proper divisors (255015715195).

21166304354213 is an equidigital number, since it uses as much as digits as its factorization.

21166304354213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255015715194.

The product of its (nonzero) digits is 311040, while the sum is 41.

The spelling of 21166304354213 in words is "twenty-one trillion, one hundred sixty-six billion, three hundred four million, three hundred fifty-four thousand, two hundred thirteen".