165919720 has 32 divisors (see below), whose sum is σ = 373957920. Its totient is φ = 66254400.

The previous prime is 165919709. The next prime is 165919751. The reversal of 165919720 is 27919561.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22495 + ... + 28945.

It is an arithmetic number, because the mean of its divisors is an integer number (11686185).

Almost surely, 2^165919720 is an apocalyptic number.

165919720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165919720 is an abundant number, since it is smaller than the sum of its proper divisors (208038200).

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

165919720 is a wasteful number, since it uses less digits than its factorization.

165919720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7105 (or 7101 counting only the distinct ones).

The product of its (nonzero) digits is 34020, while the sum is 40.

The square root of 165919720 is about 12880.9828817525. The cubic root of 165919720 is about 549.4978557366.

The spelling of 165919720 in words is "one hundred sixty-five million, nine hundred nineteen thousand, seven hundred twenty".