161809238780 has 96 divisors (see below), whose sum is σ = 389558937600. Its totient is φ = 55303967232.

The previous prime is 161809238741. The next prime is 161809238803. The reversal of 161809238780 is 87832908161.

161809238780 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 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 31 ways as a sum of consecutive naturals, for example, 81432947 + ... + 81434933.

It is an arithmetic number, because the mean of its divisors is an integer number (4057905600).

Almost surely, 2^161809238780 is an apocalyptic number.

161809238780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161809238780 is an abundant number, since it is smaller than the sum of its proper divisors (227749698820).

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

161809238780 is a wasteful number, since it uses less digits than its factorization.

161809238780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3531 (or 3529 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 53.

The spelling of 161809238780 in words is "one hundred sixty-one billion, eight hundred nine million, two hundred thirty-eight thousand, seven hundred eighty".