165646278097 has 4 divisors (see below), whose sum is σ = 174364503280. Its totient is φ = 156928052916.

The previous prime is 165646278037. The next prime is 165646278163. The reversal of 165646278097 is 790872646561.

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 a de Polignac number, because none of the positive numbers 2^k-165646278097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165646278037) 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, 4359112563 + ... + 4359112600.

It is an arithmetic number, because the mean of its divisors is an integer number (43591125820).

Almost surely, 2^165646278097 is an apocalyptic number.

It is an amenable number.

165646278097 is a deficient number, since it is larger than the sum of its proper divisors (8718225183).

165646278097 is an equidigital number, since it uses as much as digits as its factorization.

165646278097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8718225182.

The product of its (nonzero) digits is 30481920, while the sum is 61.

The spelling of 165646278097 in words is "one hundred sixty-five billion, six hundred forty-six million, two hundred seventy-eight thousand, ninety-seven".