165643351 has 4 divisors (see below), whose sum is σ = 167912512. Its totient is φ = 163374192.

The previous prime is 165643337. The next prime is 165643367. The reversal of 165643351 is 153346561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165643351 - 2¹¹ = 165641303 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 (165643301) 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, 1134471 + ... + 1134616.

It is an arithmetic number, because the mean of its divisors is an integer number (41978128).

Almost surely, 2^165643351 is an apocalyptic number.

165643351 is a deficient number, since it is larger than the sum of its proper divisors (2269161).

165643351 is an equidigital number, since it uses as much as digits as its factorization.

165643351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2269160.

The product of its digits is 32400, while the sum is 34.

The square root of 165643351 is about 12870.2506191605. The cubic root of 165643351 is about 549.1925904955.

The spelling of 165643351 in words is "one hundred sixty-five million, six hundred forty-three thousand, three hundred fifty-one".