165281720 has 16 divisors (see below), whose sum is σ = 371883960. Its totient is φ = 66112672.

The previous prime is 165281707. The next prime is 165281747. The reversal of 165281720 is 27182561.

It is a super-3 number, since 3×165281720³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2065982 + ... + 2066061.

Almost surely, 2^165281720 is an apocalyptic number.

165281720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165281720 is an abundant number, since it is smaller than the sum of its proper divisors (206602240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165281720 is a wasteful number, since it uses less digits than its factorization.

165281720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4132054 (or 4132050 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 165281720 is about 12856.1938379911. The cubic root of 165281720 is about 548.7926352685.

The spelling of 165281720 in words is "one hundred sixty-five million, two hundred eighty-one thousand, seven hundred twenty".