165996353840 has 40 divisors (see below), whose sum is σ = 391701856560. Its totient is φ = 65407516416.

The previous prime is 165996353801. The next prime is 165996353843. The reversal of 165996353840 is 48353699561.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 165996353840.

It is not an unprimeable number, because it can be changed into a prime (165996353843) by changing a digit.

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, 15479375 + ... + 15490094.

It is an arithmetic number, because the mean of its divisors is an integer number (9792546414).

Almost surely, 2^165996353840 is an apocalyptic number.

165996353840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165996353840 is an abundant number, since it is smaller than the sum of its proper divisors (225705502720).

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

165996353840 is a wasteful number, since it uses less digits than its factorization.

165996353840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30969549 (or 30969543 counting only the distinct ones).

The product of its (nonzero) digits is 20995200, while the sum is 59.

The spelling of 165996353840 in words is "one hundred sixty-five billion, nine hundred ninety-six million, three hundred fifty-three thousand, eight hundred forty".