165401663 has 8 divisors (see below), whose sum is σ = 189136032. Its totient is φ = 141693696.

The previous prime is 165401609. The next prime is 165401681. The reversal of 165401663 is 366104561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 165401663 - 2¹⁸ = 165139519 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 (165401363) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9431 + ... + 20487.

It is an arithmetic number, because the mean of its divisors is an integer number (23642004).

Almost surely, 2^165401663 is an apocalyptic number.

165401663 is a deficient number, since it is larger than the sum of its proper divisors (23734369).

165401663 is a wasteful number, since it uses less digits than its factorization.

165401663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13201.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 165401663 is about 12860.8577863220. The cubic root of 165401663 is about 548.9253539562.

The spelling of 165401663 in words is "one hundred sixty-five million, four hundred one thousand, six hundred sixty-three".