166163644399 has 4 divisors (see below), whose sum is σ = 166186752336. Its totient is φ = 166140536464.

The previous prime is 166163644397. The next prime is 166163644441. The reversal of 166163644399 is 993446361661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 993446361661 = 13 ⋅76418950897.

It is a cyclic number.

It is not a de Polignac number, because 166163644399 - 2¹ = 166163644397 is a prime.

It is a super-2 number, since 2×166163644399² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166163644397) 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, 11543179 + ... + 11557564.

It is an arithmetic number, because the mean of its divisors is an integer number (41546688084).

Almost surely, 2^166163644399 is an apocalyptic number.

166163644399 is a deficient number, since it is larger than the sum of its proper divisors (23107937).

166163644399 is an equidigital number, since it uses as much as digits as its factorization.

166163644399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23107936.

The product of its digits is 15116544, while the sum is 58.

The spelling of 166163644399 in words is "one hundred sixty-six billion, one hundred sixty-three million, six hundred forty-four thousand, three hundred ninety-nine".