165221549 has 8 divisors (see below), whose sum is σ = 174482880. Its totient is φ = 156016800.

The previous prime is 165221533. The next prime is 165221561. The reversal of 165221549 is 945122561.

It is a happy number.

165221549 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 165221549 - 2⁴ = 165221533 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 (165221519) 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, 8072 + ... + 19889.

It is an arithmetic number, because the mean of its divisors is an integer number (21810360).

Almost surely, 2^165221549 is an apocalyptic number.

165221549 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

165221549 is a deficient number, since it is larger than the sum of its proper divisors (9261331).

165221549 is a wasteful number, since it uses less digits than its factorization.

165221549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28291.

The product of its digits is 21600, while the sum is 35.

The square root of 165221549 is about 12853.8534689018. The cubic root of 165221549 is about 548.7260309890.

The spelling of 165221549 in words is "one hundred sixty-five million, two hundred twenty-one thousand, five hundred forty-nine".