163666366249 has 3 divisors (see below), whose sum is σ = 163666770807. Its totient is φ = 163665961692.

The previous prime is 163666366243. The next prime is 163666366277. The reversal of 163666366249 is 942663666361.

The square root of 163666366249 is 404557.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 159484416025 + 4181950224 = 399355^2 + 64668^2 .

It is not a de Polignac number, because 163666366249 - 2¹¹ = 163666364201 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 163666366193 and 163666366202.

It is not an unprimeable number, because it can be changed into a prime (163666366243) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 202279 + ... + 606835.

It is an arithmetic number, because the mean of its divisors is an integer number (54555590269).

Almost surely, 2^163666366249 is an apocalyptic number.

163666366249 is the 404557-th square number.

163666366249 is the 202279-th centered octagonal number.

It is an amenable number.

163666366249 is a deficient number, since it is larger than the sum of its proper divisors (404558).

163666366249 is an frugal number, since it uses more digits than its factorization.

163666366249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 809114 (or 404557 counting only the distinct ones).

The product of its digits is 30233088, while the sum is 58.

The spelling of 163666366249 in words is "one hundred sixty-three billion, six hundred sixty-six million, three hundred sixty-six thousand, two hundred forty-nine".