21166703314637 has 4 divisors (see below), whose sum is σ = 21167545929756. Its totient is φ = 21165860699520.

The previous prime is 21166703314607. The next prime is 21166703314639. The reversal of 21166703314637 is 73641330766112.

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 5078109013156 + 16088594301481 = 2253466^2 + 4011059^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21166703314637 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 (21166703314639) 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, 421269878 + ... + 421320119.

It is an arithmetic number, because the mean of its divisors is an integer number (5291886482439).

Almost surely, 2^{21166703314637} is an apocalyptic number.

It is an amenable number.

21166703314637 is a deficient number, since it is larger than the sum of its proper divisors (842615119).

21166703314637 is an equidigital number, since it uses as much as digits as its factorization.

21166703314637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 842615118.

The product of its (nonzero) digits is 2286144, while the sum is 50.

The spelling of 21166703314637 in words is "twenty-one trillion, one hundred sixty-six billion, seven hundred three million, three hundred fourteen thousand, six hundred thirty-seven".