161968609638 has 64 divisors (see below), whose sum is σ = 395002621440. Its totient is φ = 48787466400.

The previous prime is 161968609609. The next prime is 161968609639. The reversal of 161968609638 is 836906869161.

161968609638 is a `hidden beast` number, since 1 + 6 + 19 + 6 + 8 + 609 + 6 + 3 + 8 = 666.

161968609638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161968609639) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 717193 + ... + 915588.

It is an arithmetic number, because the mean of its divisors is an integer number (6171915960).

Almost surely, 2^161968609638 is an apocalyptic number.

161968609638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

161968609638 is an abundant number, since it is smaller than the sum of its proper divisors (233034011802).

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

161968609638 is a wasteful number, since it uses less digits than its factorization.

161968609638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1632970 (or 1632964 counting only the distinct ones).

The product of its (nonzero) digits is 20155392, while the sum is 63.

The spelling of 161968609638 in words is "one hundred sixty-one billion, nine hundred sixty-eight million, six hundred nine thousand, six hundred thirty-eight".