165642149 has 4 divisors (see below), whose sum is σ = 169494336. Its totient is φ = 161789964.

The previous prime is 165642143. The next prime is 165642151. The reversal of 165642149 is 941246561.

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 an emirpimes, since its reverse is a distinct semiprime: 941246561 = 2699 ⋅348739.

It is a cyclic number.

It is not a de Polignac number, because 165642149 - 2⁸ = 165641893 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165642143) 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, 1926029 + ... + 1926114.

It is an arithmetic number, because the mean of its divisors is an integer number (42373584).

Almost surely, 2^165642149 is an apocalyptic number.

It is an amenable number.

165642149 is a deficient number, since it is larger than the sum of its proper divisors (3852187).

165642149 is an equidigital number, since it uses as much as digits as its factorization.

165642149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3852186.

The product of its digits is 51840, while the sum is 38.

The square root of 165642149 is about 12870.2039222384. The cubic root of 165642149 is about 549.1912620770.

The spelling of 165642149 in words is "one hundred sixty-five million, six hundred forty-two thousand, one hundred forty-nine".