165401617 has 4 divisors (see below), whose sum is σ = 165427696. Its totient is φ = 165375540.

The previous prime is 165401609. The next prime is 165401681. The reversal of 165401617 is 716104561.

165401617 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 716104561 = 7079 ⋅101159.

It is a cyclic number.

It is not a de Polignac number, because 165401617 - 2³ = 165401609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165401917) 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, 3298 + ... + 18484.

It is an arithmetic number, because the mean of its divisors is an integer number (41356924).

Almost surely, 2^165401617 is an apocalyptic number.

It is an amenable number.

165401617 is a deficient number, since it is larger than the sum of its proper divisors (26079).

165401617 is a wasteful number, since it uses less digits than its factorization.

165401617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26078.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 165401617 is about 12860.8559979497. The cubic root of 165401617 is about 548.9253030689.

The spelling of 165401617 in words is "one hundred sixty-five million, four hundred one thousand, six hundred seventeen".