161591139860 has 24 divisors (see below), whose sum is σ = 342013378560. Its totient is φ = 64127506464.

The previous prime is 161591139851. The next prime is 161591139869. The reversal of 161591139860 is 68931195161.

161591139860 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (161591139851) and next prime (161591139869).

It is a super-2 number, since 2×161591139860² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161591139799 and 161591139808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161591139869) 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 7 ways as a sum of consecutive naturals, for example, 31806740 + ... + 31811819.

It is an arithmetic number, because the mean of its divisors is an integer number (14250557440).

Almost surely, 2^161591139860 is an apocalyptic number.

161591139860 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161591139860 is an abundant number, since it is smaller than the sum of its proper divisors (180422238700).

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

161591139860 is a wasteful number, since it uses less digits than its factorization.

161591139860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63618695 (or 63618693 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 50.

The spelling of 161591139860 in words is "one hundred sixty-one billion, five hundred ninety-one million, one hundred thirty-nine thousand, eight hundred sixty".