165409640 has 32 divisors (see below), whose sum is σ = 406006560. Its totient is φ = 60148800.

The previous prime is 165409603. The next prime is 165409663. The reversal of 165409640 is 46904561.

It is a self number, because there is not a number n which added to its sum of digits gives 165409640.

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, 187526 + ... + 188405.

It is an arithmetic number, because the mean of its divisors is an integer number (12687705).

Almost surely, 2^165409640 is an apocalyptic number.

165409640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165409640 is an abundant number, since it is smaller than the sum of its proper divisors (240596920).

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

165409640 is a wasteful number, since it uses less digits than its factorization.

165409640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375953 (or 375949 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 165409640 is about 12861.1679096418. The cubic root of 165409640 is about 548.9341783479.

The spelling of 165409640 in words is "one hundred sixty-five million, four hundred nine thousand, six hundred forty".