165613445 has 4 divisors (see below), whose sum is σ = 198736140. Its totient is φ = 132490752.

The previous prime is 165613433. The next prime is 165613447. The reversal of 165613445 is 544316561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 544316561 = 2251 ⋅241811.

It can be written as a sum of positive squares in 2 ways, for example, as 52041796 + 113571649 = 7214^2 + 10657^2 .

It is a cyclic number.

It is not a de Polignac number, because 165613445 - 2⁴ = 165613429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165613447) 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, 16561340 + ... + 16561349.

It is an arithmetic number, because the mean of its divisors is an integer number (49684035).

Almost surely, 2^165613445 is an apocalyptic number.

It is an amenable number.

165613445 is a deficient number, since it is larger than the sum of its proper divisors (33122695).

165613445 is an equidigital number, since it uses as much as digits as its factorization.

165613445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33122694.

The product of its digits is 43200, while the sum is 35.

The square root of 165613445 is about 12869.0887400779. The cubic root of 165613445 is about 549.1595372679.

The spelling of 165613445 in words is "one hundred sixty-five million, six hundred thirteen thousand, four hundred forty-five".